The following technical program is correct at time of publishing. However, given their professional commitments, a few of our speakers may be forced to remove themselves from the program or to substitute another presenter. Such a situation is regrettable and we will always try to replace a speaker with one of equivalent insight. The organizers will make every effort not to change the order of the sessions or the sequence of the presentations. However, if a situation warrants, the session

order or presentation sequence may have to be changed. The final technical program will be available on the web site closer to the event, as well as at the registration desk.

SUNDAY, OCTOBER 18, 2015 Pre-Conference Events

8:00 a.m. - 5:00 p.m. Board of Trustees McDonald

2:00 - 5:00 p.m. Registration Opens — Foyer

2:00 - 5:00 p.m. Exhibitor Set up — Laurier 5:30 - 7:30 p.m. Meet & Greet — The Bistro

MONDAY, OCTOBER 19, 2015 7:30 a.m. - 5:00 p.m. Registration — Foyer 8:00 a.m. - 5:00 p.m. Exhibitor Hall Open — Laurier

McDonald Cartier

8:00 - 9:30 a.m.

OPENING CEREMONY & PLENTARY LECTURE Artifacts from the Franklin Expedition’s Erebus

Flora Davidson, Parks Canada

9:30 - 10:00 a.m. Morning Break — Exhibit Hall

10:00 - Noon Session A Coatings and Linings

Session B Corrosion in Concrete Structures

10:00 - 10:30 a.m.

1. What the Stink? On the Scent ofSomething Big with Acid Gases and Linings

Mike O’Donoghue and Vijay Datta,

International Paint LLC

1. Strain Concentrations in CorrodedBridge Columns Repaired with

FRP Wraps Goli Nossoni

Manhattan College

10:30 - 11:00 a.m.

2. Close Encounters of the Third“Crude-Oil” Kind

Mike O’Donoghue and Vijay Datta,

International Paint LLC

2. Chloride Extraction for ReinforcedConcrete Structures

Chantal Fequiere Vector Corrosion Technologies

11:00 - 11:30 a.m.

3. Polyaspartic Urethane Coatings: Reducing Painting Costs and

Increasing Productivity Ahren Olson

Bayer Material Science, LLC

3. Field Performance of Low-shrinkage High-performance Concrete Deck at

Seaway International Bridge in Cornwall, Ontario

Daniel Cusson, NRC Canada - Construction

11:30 - Noon

4. Activated Zinc - An Innovation that Redefines the Performance of

Zinc Rich Epoxies Terence Aben

Hempel Americas, Inc.

4. Duplex 2304 Stainless Steel Rein- forcing Bar:

Properties and Applications Frank Smith Consultant

Noon - 1:30 p.m. LUNCH BREAK

1:30 - 2:00 p.m.

5. Titanium-nano Polymer and its Anti-corrosion Applications

Huanran Wang Harbin Xinke Nano Scientific & Technical

Development Co.,Ltd. China

1. The Radiolytic Corrosion of Copper Nuclear Waste Containers

Mehran Behazin University of Western Ontario

2:00 - 2:30 p.m.

6. Harsh Marine Environment Assessment of Coating Integrity and Corrosivity

Matthew Kettle Research & Development Corporation

2. Monitoring Cathodic Protection Systems in Nuclear and other

Congested Plant Craig Stevenson Apex Corrosion

2:30 - 3:00 p.m.

7. Glass Flake Usage in Protective Coatings Formulations: Is North America Behind?

Edward Malison NGF Canada Ltd

3. The Corrosion Behaviour of Copper-coated Carbon Steel

Sridhar Ramamurthy The University of Western Ontario

3:00 - 3:30 p.m. AFTERNOON BREAK — Exhibit Hall

3:30 - 5:00 p.m. Session A

Coatings and Linings (Continues) Session D

Materials Selection

3:30 - 4:00 p.m.

8. Corrosion Control – PDCA Concept Application

Alain Beaulieu Versaille

1. Between The Discovery and The Doing - FRP Pipe Commercialization

Michael Boire Fibreglass Solutions Inc.

4:00 - 4:30 p.m.

9. Development and Implementation of a Novel Method to Remove Inorganic Zinc

Coating from Low Alloy Steel Yasir Idlibi1, Barry Messer2, and

Sergio Vitomir3

ADANAC Global Testing & Inspection, Calgary, AB1

Fluor Canada Ltd., Calgary, AB2

Protocol Environmental Solutions Inc., Coquitlam, BC3

2. Investigation into the Reaction of Co-Cr-W Alloy in Amine Doped Water

Rachel Collier Deloro Stellite Co Inc

4:30 - 5:00 p.m.

10. Oscillating Chemistry During Electrochemical studies of Coated

Aluminum Beverage Can Corrosion in Neutral pH NaCl Solutions G.A. McRae and D.R. McCracken,

Carleton University

3. Advances in the Rotating Cage Method for Materials Selection in

Oil and Gas Production Allan Runstedtler CanmetENERGY

5:00 - 7:00 p.m. WELCOME RECEPTION — Exhibit Hall

TUESDAY, OCTOBER 20, 2015 7:30 a.m. - 5:00 p.m. REGISTRATION — Foyer 8:00 a.m. - 5:00 p.m. EXHIBITOR HALL OPEN — Laurier

McDonald Cartier Session E

Case Studies Session F Defence

8:00 -8:30 a.m.

1. Review of Inspection and Maintenance Programs Designed for Heavy Water

Production Unit at Raan Romag Raluca Fako

CITON

1. New Technologies and Future Challenges for the Prevention of

Corrosion in US DoD Assets George Keller

U.S. Department of Defense Corrosion Policy and Oversight Office

(Part 1)

8:30 - 9:00 a.m.

2. Study of Corrosion Failures in Copper Plumbing Systems Alan Humphreys

Simpson Gumpertz and Heger

2. New Technologies and Future Challenges for the Prevention of

Corrosion in US DoD Assets George Keller

U.S. Department of Defense Corrosion Policy and Oversight Office

(Part 2)

9:00 - 9:30 a.m.

3. Is this Really a Failure? Case Histories in Failure Analysis

David Twigg, Glencor Engineering Ltd.

3. The Future Direction of Military Coatings Beth Ann Pearson Sherwin-Williams Co.

9:30 - 10:00 a.m.

4. The Arvida Aluminum Bridge: A Follow-up visit 29 years after Repair Work

Frank Smith Consultant

10:00 - 10:30 a.m. MORNING BREAK — Exhibit Hall Session G

Research & Development Session H

Cathodic Protection

10:30 - 11:00 a.m.

1. Investigation of the Role of Iron Content on the Crevice Corrosion of Grade-2 Titani-

um using Atomic Probe Tomography. Dmitrij Zagidulin

University of Western Ontario

1. Electromagnetic Interference in Pipelines: the Influence of

Conductivity of the Pipeline Contents David Boteler

Natural Resources Canada

11:00 - 11:30 a.m.

2. On the Role of Grain Boundary Mechan- ical Property in the Intergranular Stress Corrosion Cracking Susceptibility of 310S

Exposed in Supercritical Water Yinan Jiao McMaster

2. DC Voltage Gradient Surveys for Pipeline Risk Management

Daniel Fingas Corrosion Service Co., Ltd.

11:30 - Noon

3. Integrating Corrosion Science, Engineering, and Management: Opportunities and Challenges

Sankara Papavinasam CorrMagnet Consulting Inc.

3. Solid Oxide Fuel Cells for Remote Impressed Current Cathodic

Protection Application Mike Brennan Acumentrics

Noon - 1:30 p.m. LUNCH BREAK

1:30 - 3:00 p.m Session G

Research & Development Session I Oil & Gas

1:30 - 2:00 p.m.

4. Corrosion Impact and Corrosion Awareness in Canadian National

Capital Region Sankara Papavinasam

CorrMagnet Consulting Inc.

1. Corrosion Growth Rate Management Plan considering Measurement Error

Mona Abdolrazaghi Enbridge Pipelines Inc.

2:00 - 2:30 p.m.

5. Corrosion Behaviour of Polypyrrole-coated WE43 Mg Alloy in a Modified Simulated Body Fluid Solution

Sasha Omanovic McGill University

2. Validating Metal Loss In-line Inspection using API 1163 and

CEPA Guidance Document Yan Ping Li

Enbridge Pipelines Inc

2:30 - 3:00 p.m

6. Hydrogen in metals studied by Thermal Desorption Spectroscopy (TDS)

Michael Graham NRC Canada

3. ASME PCC-2, 4.1 Compliant Composite Repairs

Tammy Bomia NRI

3:00 - 3:30 p.m. AFTERNOON BREAK — Exhibit Hall

3:30 - 5:00 p.m Session G

Research & Development Session J Inhibitor

3:30 - 4:00 p.m.

7. Corrosion -- An Accidental Choice -- When Metals Meet Living Tissue

R Winston Revie

1. Corrosion Mitigation of X-60 Type Carbon Steel in Petroleum Formation

Water under Pressure of CO2 Bassam Sheriat

Egyption Natural Gas Holding Company

4:00 - 4:30 p.m.

8. Magnesium Alloys as Promising Degradable Implant Materials in

Orthopaedic Research Sasikumar Yesudass

North-West University, South Africa

2. Experimental and Theoretical Studies on Newly Synthesized Photo-

cross-link-able Chalcones for Inhibition of Mild Steel

Baskar Ramaganthan North-West University, South Africa.

4:30 - 5:00 p.m

9. Pitfalls with Electrochemical Impedance Spectroscopy and

Equivalent Circuit Models D.R. McCracken and G.A. McRae

Carleton University

5:00 - 7:00 p.m. EXHIBITOR APPRECIATION RECEPTION — Exhibit Hall WEDNESDAY, OCTOBER 21, 2015

7:30 a.m. - 5:00 p.m. REGISTRATION — Foyer 8:00 a.m. - 5:00 p.m. EXHIBITOR HALL OPEN — Laurier

Noon- 2:00 p.m. EXHIBITOR TEAR DOWN McDonald Cartier Session K

Student Poster Presentations Session L

Round Table - Policy

8:00 -9:30 a.m.

Of students, for students, and by students (Attendance for others by

student invitation only)

Round Table Discussion on Policies on Corrosion

9:30 - 10:00 a.m. MORNING BREAK — Exhibit Hall Session K

Student Poster Presentations Session L

Round Table - Policy

10:00 - Noon Of students, for students, and by students

(Attendance for others by student invitation only)

Round Table Discussion on Policies on Corrosion

11:30 - Noon Student Poster Award and Closing Ceremony Noon - 2:00 p.m. LUNCH BREAK

2:00 - 5:00 p.m. Lab Tour Canadian National Capital Section

(CNCS) members meeting

2015 NORTHERN AREA EASTERN CONFERENCE ABSTRACTS

PLENARY LECTURE

Artifacts from the Franklin Expedition’s Erebus Flora Davidson, Parks Canada

Since the disappearance of the two ships HMS Erebus and HMS Terror, on which Sir John Franklin and his crew had set sail from England in 1845, there has been continuous search and speculation about the final resting spot of these now famous ships and their crew. Part of this mystery was solved in September 2014 when the HMS Erebus was discovered by an expedition lead by Parks Canada. The shipwreck was found resting upright where it sank to the bottom of the Victoria Straight covered by 11 meters of frigid water.

While the analysis of the shipwreck is still in its infancy, a small collection of artifact has been recovered and brought to the laboratory for conservation and study. The first artifact to be raised, the ship’s bell, is a time capsule in itself. While only the date “1845”, a simple broad arrow and bead lines are apparent, the surface tells a tale of 160 years buried at sea. Contained within the corrosion itself are further details which may provide links

that could be used to trace it to its manufacture.

It is hoped that through the process of conservation, scientific analysis and research, that the bell and other artifacts from the Erebuswill further unravel the circumstances of life aboard the ship leading up to its disappearance.

Session A: Coatings and Linings

What the Stink? On the Scent of Something Big with Acid Gases and Linings Mike O’Donoghue, PhD., and Vijay Datta, MS International Paint LLC

Epoxy lining technology has undergone highly innovative developments for tanks, vessels and pipelines in the oil patch. But just how aggressive are the sour service environments to the linings when exposure involves high molar concentrations of the acid gases H2S and CO2 and elevated temperatures and pressures? The effect of hot acid gases on high performance linings can lead to some rather intriguing results. Close Encounters on the Third “Crude-Oil” Kind Mike O’Donoghue, PhD and Vijay Datta, MS International Paint LLC

This paper compares and contrasts the accelerated laboratory autoclave (NACE TM0185) performance at 300°F (149°C), and 250 psig, of eight polycyclamine cured epoxy linings. The latter were tested for tank, vessel and pipe spool applications in the oil and gas industry. Five of the linings were commercially available and three were experimental. A modified amine-cured epoxy was also evaluated in the study, which is a lining used to transport shale oil in railcars at temperatures up to 200°F (93°C).

The hydrocarbon media employed in the testing was neither conventional nor unconventional crude, but rather the third “crude oil” kind, namely shale oil and it was obtained from the Bakken shale play.

Electrochemical Impedance Spectroscopy, immersion and adhesion testing, and visual inspection were used to evaluate the high temperature resistance, barrier properties and adhesion to carbon steel panels of two-coat thin film epoxy systems, and single coat, solvent free epoxy lining systems.

A case history is provided for a single coat epoxy lining used for transporting shale oil in railcars. Polyaspartic Urethane Coatings: Reducing Painting Costs and Increasing Productivity Ahren Olson Bayer Material Science, LLC

Polyaspartic urethane coatings have been used in industrial maintenance applications now for over a decade to protect steel structures such as bridges, oil and gas infrastructure, stadiums, etc. This coating technology is designed for improving efficiency and throughput in painting operations by allowing fewer number of coating layers, while still providing excellent asset protection. The improved efficiency and throughput generates value for the contractor along with project cost savings for the owner. Both direct/indirect cost savings can be generated through time reduction realized in the number of coats but also those generated by the speed of the return to service/handle times (less time waiting for paint to dry). Polyaspartic urethane coatings have proven their performance in numerous heavy duty applications, which will be discussed in the presentation.

The learning objectives of this presentation will include:

1. Understand what polyaspartic urethane coatings are

2. Advantages of polyaspartic urethane coatings

3. Where these coatings have been used successfully via case histories of their performance Activated Zinc – An Innovation that Redefines the Performance of Zinc Rich Epoxies Terence Aben Hempel Americas, Inc.

Zinc rich primer coatings, both organic and inorganic, are extensively used in highly corrosive environments and they are part of high performance coating systems to protect steel against corrosion. During the 60’s and the 70’s, zinc rich epoxy primers dominated the market. Later, inorganic ethyl silicate zinc primers took over this role, but nowadays it appears as if zinc epoxy primers have made a comeback. Some of the advantages of zinc epoxies compared to zinc silicates are: thy have less demanding curing conditions (epoxies will cure at low humidity), they are easier to overcoat and they are less demanding to substrate preparation prior to application.

Zinc rich epoxies are typically formulated with high loads of zinc dust, which is an expensive component and drives a large portion of these products costs. According to ISO 12944 a zinc rich coating contains more than 80% zinc by weight in the dry film, and SSPC Paint 20 defines zinc rich as more than 65%, and requires 85% or greater to meet the Level 1 category. However, in the last decade studies have shown that only about one third of the zinc in zinc rich epoxies is utilised for galvanic protection of the steel, making poor utilization of an expensive component and leaving much room for improved anti-corrosive performance.

The protective mechanism of zinc rich coatings is believed mainly to be based on cathodic protection provided by the zinc dust in the paint. When a coating system containing a zinc rich primer is exposed to a corrosive environment, rust creep and blistering are among the most important failure mechanisms considered. Many accelerated exposures will not, within their exposure time, show the defects visually on intact coated surfaces. Therefore, behaviour of the coatings involving artificially made damages, i.e., scores, are given significant considerations in the development of efficient anti-corrosive primers. Many prequalification tests (e.g. ISO 12944, ISO 20340, NORSOK M501 Rev.6) are based on rust creep and blistering as well as detachment from scores.

An intensive research and development effort has produced a new innovative technology that increases the activation of the zinc in zinc rich epoxies. It will be demonstrated that activated zinc technology achieves a combination of galvanic, barrier and inhibition mechanisms that greatly enhances the anticorrosive properties of zincrichepoxieswithoutanynegativeimpactontheirtraditionaladvantages, andprovidesadditionalimprovement in mechanical performance and tolerance to application in higher film thicknesses. The performance properties of the new generation primer have been proven with real results from different corrosion tests (ISO 12944, Salt Spray Test according to ISO 9227, NACE Cracking Test TM0304, Norsok) which will be presented.

Titanium-nano Polymer and its Anti-corrosion Applications Huanran Wang Harbin Xinke Nano Scientific & Technical Development Co.,Ltd. China

With challenges of different corrosion problems and environments, new formulations of anti-corrosion coating are developed to address these requirements. In this paper, a new anti-corrosion coating, Titanium-nano polymer (TNP), is introduced. Two successful applications are presented to prove TNP’s unique anti-corrosion performance.

To prepare TNP, Titanium is transformed into nanometer level by ultra-attenuation, which greatly improves the activity of titanium surface. Meanwhile, double bonds of organic compounds are opened to form free bonds. Thus, both of them combine together to form TNP. It has very unique properties such as strong penetration resistance, high corrosion resistance, good anti-fouling performance, thermal conductivity, temperature resistance, wearing resistance, and water resistance.

TNP can be widely applied as an anti-corrosive coating in many areas: petroleum and chemical industry, ocean

structures, food industry, etc. Application of anti-corrosive TNP coating in heat exchangers.

Different protection methods were adopted in the corrosion of refinery heat exchanger in different corrosion environment. After many years efforts, some significant results and economic benefits has achieved. However, the oil and gas corrosion of the heat exchanger has not been solved completely.

Based on the corrosion analysis, a series of experiments are conducted to find a new anti-corrosive coating for the heat exchanger. Modified furan coating, polyolefin, polyurea and TNP’s samples are tested in the heat exchanger for 180 days. The final result shows that comparing to other materials, TNP does not changes and stays stable. Therefore, TNP coating is adopted to multiple sets of heat exchanging equipment. After 8 years, anti- corrosive coating of tube inner and outer wall does not change. And there are no fouling and rust existing.

The result showed that the TNP coated tube increased heat transfer coefficient by 66.54% more than the uncoated carbon steel tube and by 49.97% more than the epoxy anime coated heat exchanger. With TNP, each heat exchanger increases the service life to 2-3 times than normal. Application of TNP coating in acid water tanks in sulphur facilities of oil refinery, acid water tanks suffer from serious corrosion. Epoxy resin coatings were adopted as the anti-corrosion coating, but it failed by blistering, softening or cracking and only lasted less than 3 months. In the tank, the premature perforations are mainly concentrated on the bottom and the welding seams of the wall of the tank. It makes the water tanks scrapped for two years and pollute to environment as well.

To select the suitable anti-corrosive coating, 5 kinds of coatings (modified furfural coating, poly vinyl coating, modified epoxy, poly urethane coating) are chose and experiments are carried out. The tests were lasted from 34 to 127 days. The result shows that TNP has the best performance on corrosion protection in the acid water tank. Therefore, TNP is installed for inner wall corrosion of acid water tank. After six years, the anti-corrosive coatings are integrity and the coating surface is gloss, has no peeling, blistering, cracking, and chipping off. There is no corrosion residual adhering to the surface of anti-corrosion coating. It solves the corrosion problem and provides a good solution for corrosion in petrochemical acid tank.

Harsh Marine Environment Assessment of Coating Integrity and Corrosivity Matthew Kettle Research & Development Corporation (RDC)

This paper describes the preliminary work assessing the severity of atmospheric corrosion at the RDC Coastal Exposure. The project combines a year of environmental and corrosion testing in Argentia, NL to generate a model predicting rates of atmospheric corrosion. Evaluating the temperature, humidity, rainfall, solar incidence, chloride and SO2 deposition, wind speed, and the integrity of a three coat zinc rich coating system through an extensive field test program, the key factors for the corrosion mechanism for this location will be identified and used as the model inputs. The model will be augmented using an aerodynamic study of the site using computational fluid dynamics to predict wind speeds and conditions at various points on a four acre area. This will then allow the risk based model to be validated using significant field testing.

Glass Flake Usage in Protective Coatings Formulations: Is North America Behind? Edward Malison NGF Canada Ltd

Using currently available technical and commercial data, this presentation will take a closer look at the reasons why it is believed that Europe and Asia, compared to North America, have a higher proportion of infrastructural and large asset coating projects using glass flake in coating formulations. Those asset owners are realizing the benefits such as lower DFT with equal or better endurance performance and better physical properties such as improved impact resistance, higher dimensional stability and reduced permeability. The commercial benefits include reduced application times that translate into less asset downtime, wet-on-wet application capabilities and less coating use and reduced overspray per square foot of application. The addition of glass flake to most existing corrosion protection coating formulations simply involved adding a specific glass flake, with little or no

change to the rest of the formulation. Based on advances in glass flake manufacturing technology, almost all liquid coating spray equipment can handle high loading of glass flake.

Corrosion Control – PDCA Concept Application Alain Beaulieu Versaille

Since 1996, when I received my NACE certification, I have observed that many coating project had suffer a lot of problems regarding either; budget, schedule, safety, environment or quality because of a lack of project preparation or planning.

Actually, to decrease and control problems during the execution of a project, it would be very appropriate to implement the continuous improvement concept as shown in the OHSAS 18001 Standard – PDCA.

P: Plan

D: Do

C: Check

A: Act Using this concept with great diligence would help any project manager in achieving a project with the success expected.

First, the most important task of a project is the preparation/planning (Plan) in order to reduce the uncertainties. During the preparation, the corrosion program manager would look at certain points like: What kind of project it is? Who will be involve? Many task project? Manager? Professional? Workers? What is the environmental issue? Lead abatement? Over a river? In an urban area? Health and safety issue? Industrial hygiene issue? Time frame available for the project? Procedures – H&S, Environment, Quality, Job Plan Budget needed to achieve the project?

Having an excellent knowledge of the project will allow the project manager to establish comprehensive written procedures. If all of those questions are clearly defines and answered, the uncertainties related to the project will be at a very low level and will provide also, a better cost control.

Second, the project manager will have to implement (Do) those procedure using pre-job information meeting, training, in order to make sure that everyone involve in the project, from the management, to the workers will be on the same page.

Third, during the execution of the project, a good survey (Check) is necessary in order to verify if the written procedures are effective. In order to verify it, the project manager will have to use professionals like; NACE Certified Coating Inspector – Specific Project Quality Procedure Engineer – Job Planning, Production Safety Officer – Specific Project Health and Safety Procedure Environmental Officer – Specific Project Environmental Procedure. The use of those professional would be essential all along the execution the project, in order to be proactive and verify if the procedures works.

And finally, in order to achieve the project within the expectation, we have to address (Act) any problem find during the survey of the activities related to the project.

Let’s see how it could be used during a coating project and… Development and Implementation of a Novel Method to Remove Inorganic Zinc Coating from Low Alloy Steel Yasir Idlibi1, Barry Messer2, and Sergio Vitomir3

ADANAC Global Testing & Inspection, Calgary, AB1

Fluor Canada Ltd., Calgary, AB2

Protocol Environmental Solutions Inc., Coquitlam, BC3

Inorganic zinc coating was applied to partially fabricated low alloy, 2-1/4 Cr-1MoV, high temperature, hydrogen reactor vessels for long-term storage corrosion protection prior to final welding and Post Weld Heat Treatment (PWHT) at 690-720°C (1274-1328°F). The coating was removed to below 1 PPM to mitigate known embrittlement and weld cracking that can occur after welding and PWHT. Typical blasting and etching procedures were unable to effectively remove the coating. The need for complete coating removal led to the development of a novel, environmentally friendly method to remove the inorganic zinc to trace levels.

The success of this novel development is the first-known method of inorganic zinc silicate coating removal to trace levels below 1 PPM. This method can be utilized in restoration projects of bridges and structural steel where abrasive blasting is not practical or environmentally unsafe. Oscillating Chemistry During Electrochemical studies of Coated Aluminum Beverage Can Corrosion in Neutral pH NaCl Solutions G.A. McRae, D.R. McCracken Mechanical and Aerospace Engineering, Carleton University, ON, Canada, K1S 5B6

Degradation and corrosion is reported of samples of coated aluminum beverage-can material in neutral sodium- chloride solutions. A non-epoxy water-borne coating has been used, and exposed to concentrated NaCl, 1 M and 0.1 M. Before being readily visible, electrochemical impedance spectrometry (EIS) detected breaching and penetration of the coating, followed by pitting corrosion of the underlying aluminum. The system chemistry oscillated between passivation and corrosion, producing many spikes in Bode plots and causing impedances to randomly rise and fall. Samples displayed many pits and through holes. The overall rates of degradation and corrosion were controlled by an intermittently passivating oxide which formed over the flaws and pits. Oxide trees were observed to grow out of pits, and these were periodically released to float away in the bulk solution. A single measurement of impedance at one time can be misleading and is not be a good indicator of coating quality. Inhomogeneous and changing oxygen concentrations in pits may power the oscillating corrosion process. Positive phase angles are symptoms of corrosion of the underlying aluminium. A rate determining chemical reaction is accelerated by anodic polarization, but does not immediately stop or reverse during the following cathodic polarization. This causes a positive phase angle at a period corresponding to the half-life of the rate determining chemical reaction.

Session B: Corrosion in Concrete Structures

Strain Concentrations in Corroded Bridge Columns Repaired with FRP Wraps Goli Nossoni Manhattan College

Baiyasi and Harichandran (2001) experimentally investigated the effect of using bonded and unbonded glass and carbon FRP (GFRP and CFRP) wraps to repair corroded concrete cylinders columns. Their study was focused on the strains generated in the FRP wrap due to continued corrosion when the FRP wrap is bonded and unbonded. They used an accelerated corrosion test and found that stress concentrations occurred in the bonded FRP in the vicinity of reinforcing bars. Their laboratory scale study showed that sustained stress concentrations, if sufficiently high, may cause stress rupture of the glass FRP wrap. However, the stress level they observed may not be reached in full-scale bridge columns. In this study, finite element (FE) analysis was used to model the laboratory samples Baiyasi and Harichandran studied. Through a calibration process, the corrosion-induced expansion was modeled as an equivalent thermal expansion of the reinforcing bars. The FE analysis confirmed that stress concentrations occur in bonded FRP wraps adjacent to the reinforcing bars and that unbonded wraps relieve these stress concentrations. Since the laboratory results showed the highest stress concentration for

GFRP, FE analysis was then conducted on a full-scale bridge column wrapped with GFRP to assess the effect of stress concentration around a corroded bar in real bridges. The results indicate that stress corrosion in bonded glass FRP wraps due to ongoing corrosion should not be a concern in real bridge columns.

Chloride Extraction for Reinforced Concrete Structures Chantal Fequiere Vector Corrosion Technologies

Chloride extraction process has been developed over 40 years ago and been used in Canada for the first time in the early 1990’s. Chloride extraction addresses the problem of chloride ion contamination at the reinforcement level in reinforced concrete by repelling the chloride ions and transporting them to the concrete surface, therefore reducing the electrolyte ions concentration around the steel. The process can be used on vertical pier surfaces without impacting the structure use in any way during treatment. It is a one-time intervention that offers the possibility of significantly increasing a structure’s longevity by halting the corrosion process without the use of a permanent external source of energy as required with impressed current. Case studies of structures that have been monitored over 20 years after receiving a chloride extraction will be presented.

Field Performance of Low-shrinkage High-performance Concrete Deck at Seaway International Bridge in Cornwall, Ontario Daniel Cusson National Research Council Canada – Construction

An innovative high performance concrete was developed for bridge deck applications requiring long service lives in aggressive corrosive environments. Several technologies were used in the formulation of this concrete to achieve very low shrinkage, low permeability, and superior mechanical properties. Pre-soaked porous fine lightweight aggregate for internal curing, combined with a shrinkage-reducing admixture, were used as a cost- effective measure to prevent shrinkage cracking and reduce chloride-induced rebar corrosion in concrete bridge structures. Performance prediction models calibrated on extensive laboratory data predicted useful service lives of high performance reinforced concrete bridge decks exposed to severe chloride environments to be over 100 years. Life cycle cost analyses estimated 65% savings in long-term maintenance costs when compared to typical bridge decks made of normal concrete. This paper presents the early field performance measurements conducted at the new Canal Bridge in Cornwall, Ontario, where the concrete was used to build the deck slab in July 2012. Vibrating wire strain sensors were embedded in the deck to monitor the strain and temperature during and after construction. After a few years of monitoring, the results indicate that the only volumetric changes in the concrete slab are due to temperature changes, since autogenous and drying shrinkage strains were found to be negligible.

Duplex 2304 Stainless Steel Reinforcing Bar: Properties and Applications Frank Smith Consultant

Duplex 2304 (UNS S32304) stainless steel reinforcing bar (rebar) for concrete construction provides a useful combination of strength, ductility, resistance to chloride attack and low life-cycle cost. Several highway bridges have been built during the last 6 years using this rebar alloy. The properties and applications of Duplex 2304 rebar will be presented.

Session C: Nuclear Power

The Radiolytic Corrosion of Copper Nuclear Waste Containers Mehran Behazin

University of Western Ontario

Most international solutions to the problem of high level nuclear waste disposal involve its encapsulation in sealed containers and emplacement in a deep geologic repository. In Canada disposal in steel containers with a thin outer copper coating is being considered. Although these containers provide radiation shielding one of potential issues with this design is the effect of gamma-radiation on corrosion of copper exposed to the repository environments.

The repository environment will evolve from (i) an aerated vapour phase to (ii) a potentially oxidizing saturated phase and, eventually, (iii) an anoxic saturated phase. A comprehensive project is underway to evaluate the influence of gamma radiation (from the decay of radioactive fission products in the used fuel) on the redox activity of the environment and copper corrosion. The goal is to develop a model to assess the extent of corrosion damage of a waste container due to radiolysis effects. This will allow an adequate copper coating thickness to be specified.

Model calculations and validation experiments involving the gamma-radiolysis of humid air and highly saline ground waters are being carried out to determine potential impact of g-radiolysis on the environments anticipated in a Canadian repository. This will provide the data required to quantify and interpret corrosion/electrochemical experiments conducted under simulated repository conditions.

In parallel with radiolysis studies electrochemical and corrosion experiments are being performed in aerated vapour and aqueous anoxic solutions at various radiation dose rates, as well as in aqueous solutions containing oxidants produced by g-radiolysis (e.g., H2O2, HNO3, ClO-). Corrosion potential, polarization resistance and surface analytical measurements are being performed to determine corrosion mechanisms and rates and to interpret the time evolution of the corroding system.

The morphology and composition of corrosion products are being analyzed using scanning electron microscopy (SEM), energy dispersive X-ray analyses, and Raman and X-ray photoelectron spectroscopies, and the extent and distribution of corrosion damage are being investigated using focused ion beam (FIB) cut cross sections, profilometry and confocal scanning laser microscopy.

A general overview of the project along with selected experimental and modelling results will be presenting in this conference.

Monitoring Cathodic Protection Systems in Nuclear and other Congested Plant Craig Stevenson Apex Corrosion

Nuclear and other power plant have particular characteristics that make monitoring of cathodic protection systems particularly onerous. The common use of a variety of materials from pressure pipe, cast iron and extensive electrical grounding results in a complex mixed metal corrosion cell where often the important piping is the anode of the corrosion cell. The absence of electrical isolating fittings on piping and the common practice of connecting the steel piping to the extensive electrical ground is a practice found not only in nuclear plant, but most power plant as well as oil and gas refineries, pumping stations and tank farms. The paper discusses the implication of mixed metal corrosion cells, absence of isolation on the measurement of the performance of cathodic protection systems and the difficulties of determining the true structure to electrolyte potentials and monitoring cathodic protection systems.

The Corrosion Behaviour of Copper-coated Carbon Steel Sridhar Ramamurthy The University of Western Ontario

Copper-coated steel containers are currently being considered by the Nuclear Waste Management Organization (NWMO) for the permanent disposal of used nuclear fuel. Based on extensive studies of a series of coating options,

two preferred coating methodologies have been adopted: (i) electrodeposition for the container prior to loading with used nuclear fuel, and (ii) cold spray coating for sealing the final closure weld after filling the container with the fuel. One of the life-limiting factors for these containers will be their long-term corrosion performance, since regulations require containment be achieved for many thousands of years after emplacement.

Since extensive information exists on copper corrosion, including under waste disposal conditions, a program is underway to demonstrate that the corrosion of electrodeposited and cold-spray deposited copper can be described by this database. The coating characteristics of variously formed coatings are being determined using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) both directly on the coatings and on polished cross sections. Of key importance are the defects in the coatings, the quality of the coating/steel interface and the adherence of the coating to the steel substrate. A series of long-term electrochemical and corrosion monitoring experiments are being conducted on annealed cold spray (CSA) and electrodeposited (ED) coatings and wrought copper specimens in 3.0 mol/L NaCl solution. These experiments are being conducted under three sets of conditions: (i) totally anaerobic conditions to simulate the anticipated long-term disposal conditions; (ii) Ar-purged conditions to investigate the influence of traces of dissolved copper; and (iii) oxygenated followed by deaerated conditions to simulate the early exposure period when such an evolution of redox conditions is expected. In these experiments the evolution of corrosion potential and polarization resistance are being followed. In addition, the chemical and physical nature of the corrosion products are being characterized by SEM/EDX, Raman spectroscopy, and other surface analytical techniques.

Session D: Materials Selection

Between The Discovery and The Doing - FRP Pipe Commercialization Michael Boire Fibreglass Solutions Inc.

Fibreglass Reinforced Plastic (FRP) pipe has been used for over 60 years, starting in the late 1940s in America. Some of the first applications were in Oil and Gas, primarily gathering and process lines. Since then, FRP pipe has been successfully used in many and increasingly varied services. Acceptance has been uneven even as the available technology has grown rapidly. This technology comprises not only the science and engineering of products and manufacturing methods but also testing, inspection and lifespan management. Between the science and engineering of materials and making FRP piping products and their use lies the phase of commercialization; between the discovery and the doing lie many details and decisions.

Commercialization can be seen as a social and technical process. Between discovering a technology that may be profitable and applying it, a convoluted path may be followed. Many decisions are required at nodes where features of the technology and aspects of the society into which it is being launched must be considered if the commercialization is to succeed. Understanding these ‘socio-technic” systems is the work of market development. In the case of FRP piping systems, the technology is much more varied than the existing commercial applications. Many ask why X plastic and Y glass is not used in FRP that is commercially available. Others are frustrated that the temperature limits of products being offered is limited to Z when they know technology exists for much higher services. A significant challenge to effective use of FRP is the dominant culture of metallic pipe use.

By commercialization, in this context, we mean not only “To organize something for a profit” nor simply “Getting a product to market” but more inclusively, preparing a system of technologies that will lead the product to be widely and generally accepted. This paper provides an overview of bringing new FRP pipe technology to market from the discovery to the doing that, in turn, supports material selection evaluations where these products are being considered.

Investigation into the Reaction of Co-Cr-W Alloy in Amine Doped Water Rachel Collier Deloro Stellite Co Inc

Co-Cr-W alloys, such as Stellite 6 (UNS R30006), have long been used in various industries for high-temperature corrosion and wear applications. In some instances, the alloys are used in power plants where they come into contact with boiler feedwater doped with amine derivatives.

The corrosion resistance of a Co-Cr-W alloy in an amine solution is studied in this work. In addition, pure cobalt is chosen to be compared with. According to ASTM G59, a potentiodynamic polarization test is conducted in two different electrolytes: 10ppm morpholine at pH9.5, and pure water at pH9.5. The results aim to establish the reformation of the protective oxide layer by comparing the reactivity in the two solutions. Advances in the Rotating Cage Method for Materials Selection in Oil and Gas Production Allan Runstedtler CanmetENERGY

Corrosion of pipe and equipment materials in oil and gas production is a significant concern to the industry. Overcoming this challenge through better materials selection is complicated by a shortage of laboratory methods that can simulate service conditions. In particular, the effects of flow and of multi-phase fluids – including water, oil, acid gases and solids such as sands and clays – are difficult to incorporate into laboratory tests. One method with the potential to meet these requirements is the Rotating Cage, in particular when conducted within an autoclave.

A recently completed characterization of the wall shear stress in the Rotating Cage is presented in a chart that is similar to the Moody Diagram for pipe flow. This provides a key component in the interpretation of Rotating Cage experiments for service conditions. Proposed modifications to the Rotating Cage to suspend solids and emulsify oil are also presented. The effect of one proposed design is examined by experimental proof-of-concept and computational fluid dynamics simulations.

Session E: Case Histories

Review of Inspection and Maintenance Programs Designed for Heavy Water Production Unit at Raan Romag Raluca Fako CITON

Located in the S.W. of Romania, the Heavy Water Production Facility (RAAN ROMAG PROD) was, and remains, an important achievement of the Romanian Nuclear Program. With a capacity of 360 t/y heavy water, this unit is currently the main heavy water producer in the world, and, therefore, a potential major vendor of heavy water for all CANDU type reactors worldwide. The isotopic exchange facilities were commissioned in 1988. On 17th July 1988, the first batch of nuclear grade heavy water was produced for CANDU reactors. Hence, this equipment has a significant service life of more than 50,000 real service hours. Isotopic exchange technology involves the use of large volumes of gaseous hydrogen sulfide, an extremely corrosive and toxic gas. Consequently, safety and security are key issues for the production unit ---- along with increasing the heavy water production efficiency. This paper gives a short review of the inspection and maintenance programs developed for the isotopic exchange columns in accordance with the Romanian regulatory framework on pressure vessels.

This paper demonstrated the efficiency of past inspection, maintenance and repairs programs for some of the pressure equipment at RAAN ROMAG PROD. It was possible to recover the capability of the equipment by weld- overlay repairs in those areas reported as non-conforming areas after examination (due to corrosion – erosion phenomena).

Study of Corrosion Failures in Copper Plumbing Systems Alan Humphreys

Simpson Gumpertz and Heger

Several corrosion failures in copper plumbing systems have been recently investigated. In each case, a failure analysis study was conducted in order to elucidate the micromechanism of failure. These failure mechanisms have included hot water pitting, erosion-corrosion, and stress corrosion cracking. This talk will outline these mechanisms and discuss how improved plumbing design could have prevented these failures. Is this Really a Failure? Case Histories in Failure Analysis David Twigg Glencor Engineering LTD

Material failures can take many forms and in a number of cases, the plant or equipment owner does not believe a failure has occurred or is even possible. Through a series of case histories, various material failures are explored, all of which could have been avoided by simple adherence to basic corrosion principles. Failures related to underground piping, copper alloys, bogus materials, paper machine equipment, building water systems and swimming pool components will be outlined.

The Arvida Aluminum Bridge: A Follow-Up Visit 29 Years after Repair Work Frank Smith Consultant

The Arvida Aluminum Bridge in Saguenay, Quebec, the world’s first long-span aluminum road bridge, was completed in 1950. During its first 30 years in service, the bridge suffered corrosion damage which appeared to have been caused by road salt run-off. Repairs were carried out in 1985-6. In the fall of 2014, a visit was made to the bridge to check on the long-term efficacy of the repair work. The findings of that visit will be presented.

Session F: Defence

New Technologies and Future Challenges for the Prevention of Corrosion in US DoD Assets Dr. George Keller U.S. Department of Defense Corrosion Policy and Oversight Office

(Part 1 and 2)

The direct cost of corrosion of United States Department of Defense (DoD) assets is approximately $22.5B annually. Corrosion also negatively impacts availability and safety of weapon systems and infrastructure. As a result, the DoD Corrosion Policy and Oversight Office is aggressively pursuing research programs and technology insertion projects focused on reducing these impacts. While significant progress has been made over the last 10 years, challenges to the development and implementation of new technologies remain.

Recent technology implementation successes in the areas of conductive gaskets, non-chrome coatings, and dehumidification systems will be presented, among others. Research progress in the areas of accelerated testing, predictive modeling, and corrosion fatigue will also be presented.

Technological challenges remain but are being incrementally overcome. However, some of the most daunting challenges in the area of corrosion control are non-technical in nature. These include defining performance requirements, securing sufficient and stable resources and funding, developing a culture of collaboration, and communicating results to name a few. These issues will be discussed and potential methods for overcoming them presented.

The Future Direction of Military Coatings

Beth Ann Pearson Sherwin-Williams Co.

The Department of Defense, in combination with Industry, defines the future direction of both military powder and liquid coatings.  Specific emphasis and research continues to be focused on corrosion control and environmental advancements. In support of the DoD’s Corrosion Prevention and Mitigation Strategic Plan, areas under focused development include: 1). The first direct-to-metal technology identified as an approved chemistry classified under the epoxy coatings qualified to MIL-PRF-22750. Challenges as a DTM are associated with maintaining durability, adhesion, and being dependent on the skill and knowledge of the formulator.

2). The advancements in Powder Coatings, expanding with MIL-PRF-32348, having led to the approved use of powder primers with liquid topcoats, in DTM applications, and further expanding to development of a CARC powder topcoat. In addition, the naval spec, MIL-PRF-24712B has been revamped and released, being inclusive of multiple technologies and types.

3). Chrome-Free Coatings, specifically having two main pathways developed- one focusing on new wash primer and conversion technologies, and a second method with the use of metal rich technologies.

4). The long-term concern with conversion coatings and chemical pre-treatments are being addressed with the release of the TT-C-490 specification. This specification is detailed and comprises many options for ease and completeness of use for coating of military assets.

Session G: Research and Development

Investigation of the Role of Iron Content on the Crevice Corrosion of Grade-2 Titanium using Atomic Probe Tomography. Dmitrij Zagidulin University of Western Ontario

Titanium (Ti) is known for its great strength, low density and excellent corrosion resistance. These desirable properties have led to a variety of applications for this material such as gas turbines, aircraft structures and drilling equipment. Due to the presence of a passive oxide film, Ti exhibits outstanding resistance to general corrosion. However, breakdown of this film under occluded conditions can lead to rapid crevice corrosion.

Grade-2 titanium (Ti-2) is a commercially pure α-phase material with some Fe impurities. The Fe content has been shown to have a significant effect on the microstructure and an unpredictable effect on the crevice corrosion behavior. In this study, the crevice corrosion behaviour of Ti-2 containing 0.078 wt.% Fe has been studied in an aerated 0.27M NaCl solution at 70 C using a galvanic technique in which the creviced electrode is coupled to a much larger counter electrode of the same material through a zero resistance ammeter. This arrangement allows the crevice current due to oxygen reduction on the counter electrode to be monitored throughout the experiment.

Comparison of the weight gain (due to deposition of TiO2.2H2O within the crevice) to the amount of charge consumed by oxygen reduction on the counter electrode shows that 60% of the corrosion is supported by proton reduction inside the crevice. SEM analysis of a polished cross section of the crevice shows propagation proceeded intergranularly.

While TEM and SIMS imaging of the sample prior to corrosion could not detect any impurities in this material, Atomic Probe Tomography (APT) performed on grain and grain boundaries showed distinctive segregation of Fe to the grain boundaries. This suggests that the intergranular corrosion is driven by the catalysis of proton reduction at the Fe locations within the grain boundary.

On the Role of Grain Boundary Mechanical Property in the Intergranular Stress Corrosion Cracking Susceptibility of 310S Exposed in Supercritical Water Yinan Jiao McMaster

The goal of this study is to develop a methodology to quantify the degree of grain boundary mechanical property in degraded (thermally-treated/irradiated) Type 310S stainless steel in order to be used as a predictive ‘signature’ for assessing intergranular stress corrosion cracking (IGSCC) susceptibility in supercritical water (SCW). Samples of 310S stainless steel were solution annealed (1060°C for 1 h + water quench), sensitized (650 °C for 100 h) to precipitate grain boundary carbides and thermally-treated (800 °C for 1000 h) to precipitate intra-grain and grain boundary carbides and sigma phase. Thermally-treated 310S materials will then irradiated using 3.4 MeV protons to 3 dpa. The intergranualr corrosion (IGC) susceptibility of the thermally-treated material was evaluated using: hardness/YS measurement, nano-indentation and nano-scratch tests. The susceptibility to IGSCC of the thermally-treated material was evaluated using slow strain rate testing (SSRT) in 25 MPa SCW at 500 °C with 8 ppm dissolved oxygen in an autoclave flow loop 200 mL/min.). This paper will present the results of our attempt to correlate the IG mechanical property with IGSCC susceptibility. The results will be discussed within the context of the role played by the degree of grain boundary hardening in the overall IGSCC mechanism.

Integrating Corrosion Science, Engineering, and Management: Opportunities and Challenges Sankara Papavinasam CorrMagnet Consulting Inc.

This presentation will discuss how scientist, corrosion engineer, and manager typically approach corrosion control. This presentation will use the application of electrochemical techniques to measure and monitor corrosion as an example. It will brief several standards on the application of electrochemical techniques for corrosion control including ASTM G3, ASTM G46, ASTM G59, ASTM G61, ASTM G96, ASTM G100, ASTM G102, ASTM G150, ASTM G199, NACE 3T199, and NACE Publication 31014; highlight the application and misapplication of electrochemical techniques in the laboratory and in the field; and will summarize specific areas where electrochemical techniques excel and where their use is limited. This presentation will also highlight the importance of integrating scientific, engineering, and managerial approaches of controlling corrosion.

Corrosion Impact and Corrosion Awareness in Canadian National Capital Region Sankara Papavinasam CorrMagnet Consulting Inc.

Several countries have published the cost of corrosion over the past 50 years. The most recent and elaborate survey was done in USA. Almost all surveys have indicated direct cost of corrosion to a nation to be around 3% of GDP. NACE international is currently undertaking the impact of corrosion worldwide. The survey results are anticipated in 2016. This presentation will summarize corrosion impact and corrosion awareness in Canadian national capital region. It will discuss various sectors affected by corrosion in the National capital region, present the level of awareness of corrosion among various stakeholders, and provide general guidelines to increase corrosion awareness.

Corrosion Behaviour of Polypyrrole-Coated WE43 Mg Alloy in a Modified Simulated Body Fluid Solution Sasha Omanovic McGill University

Mg alloys are attractive materials for biodegradable implant applications due to their good biocompatibility and suitable mechanical properties. However, Mg alloys corrode too fast in the physiological environment, leading to premature decrease in the implant mechanical properties and possible implant failure. In addition, hydrogen

gas is formed at quantities that cannot be bio-absorbed by the body, leading to hydrogen gas accumulation and delaying the healing process. Current research efforts to control the corrosion rate of Mg-based implants can be divided in two areas: (1) development of new Mg alloys with improved biocompatibility and corrosion resistance and, (2) development of protective coatings. Recently, the use of polypyrrole (PPy) coatings for tailoring the degradation rate of Mg-based implants has been suggested. PPy is an electrically-conductive polymer with well-known biocompatibility that offers the possibility of controlled release of a variety of drugs and with a potential for intelligent corrosion protection. However, little information on the corrosion mechanisms of PPy-coated Mg alloys in complex solutions, such as simulated body fluids (SBFs), has been provided. Furthermore, the effect of variation of relevant electrolyte parameters, such as pH and concentration of electrolyte components (e.g. dissolved CO2 and Mg2 species) on the alloy corrosion behaviour has not been reported.

In this work, PPy coatings were electrochemically synthesized on WE43 electrodes by cyclic voltammetry in a sodium salicylate containing solution. The corrosion behaviour of PPy/WE43 Mg alloy in a modified simulated body fluid (m-SBF) at 37 ºC was investigated for an immersion time up to 120 h. Daily electrolyte renewal was performed with the aim to closer simulate physiological homeostasis. Interfacial processes and corrosion mechanisms were investigated by electrochemical impedance spectroscopy (EIS). The PPy/WE43 electrode corrosion kinetics were investigated by monitoring the electrolyte concentration of dissolved Mg2+ by inductively coupled plasma optical emission spectroscopy (ICP-OES) and the production of H2 gas, and the results were compared to the data obtained by EIS. The corroded surface morphology and the corrosion layer thickness were characterized by scanning electron microscopy (SEM), while the surface chemical composition of the corroded samples was characterized by energy-dispersive spectroscopy (EDS) and attenuated total reflectance Fourier transformed infrared spectroscopy.

Hydrogen in Metals Studied by Thermal Desorption Spectroscopy (TDS) Micahael Graham NRC, Canada

This paper presents Thermal Desorption Spectroscopy (TDS) of hydrogen desorption from various metals and alloys [ Au, Pd, Cu, Ni, Zr, Y, stainless steel and ODS (oxide dispersion strengthened) alloy] after long-term exposure (up to 20 years) to ambient air at room-temperature. Of the metals studied only gold does not contain a measurable level of hydrogen. For polycrystalline metals there is a strong correlation between the amount of hydrogen in the metal and the tendency for oxidation of the metal.

Corrosion -- An Accidental Choice -- When Metals Meet Living Tissue R Winston Revie

R&D on metals in living tissue will be discussed as the background of 50 years of study in corrosion science and engineering. In the context of achieving research goals, collaborations and innovations will be discussed, along with four types of challenges; scientific, design, organizational, and financial. Trends in challenges from the 1960s to the present time and the changing innovations that are required will be reviewed, with reference to the evolution of organizational priorities focused on decreasing costs, increasing efficiencies, and extending the lives of people.

Magnesium Alloys as Promising Degradable Implant Materials in Orthopaedic Research: Sasikumar Yesudass North west University, South Africa

Magnesium alloys are commonly used in making automobile parts due to their unique properties, and often cause fire hazards or surface degradation during the manufacturing processes, such as machining, melting or heat treatment. Magnesium and its alloys are widely used now in the manufacturing of orthopedic implants

as prostheses for joint replacement because of their high corrosion resistance and excellent biocompatibility. However, they lack in bone bonding ability and leads to higher rate of osteolysis and subsequent loosening of implants. In order to enhance the bone-bonding ability of these alloys, various coatings methods and surface-modification techniques are generally employed. Among them, surface modification methods play a major role in the bio-implant materials. The present investigation is mainly concerned with the surface modification of AZX310, AZ91D and AM50 alloys using alkali (NaOH) and hydrogen peroxide (H2O2) followed by subsequent heat treatment to produce a porous-gel morphological layer which enhances osseointegration. The morphological behavior was examined using atomic force microscopy (AFM), and scanning electron microscopy (SEM) coupled with energy dispersive x-ray analysis (EDX). The in-vitro characterization of all the specimens was evaluated by immersing the specimens in simulated body fluid (SBF) solution to assess the apatite formation over the magnesium alloy surfaces. The apatite formation was confirmed by XRD, SEM/EDX and Fourier transform infrared spectroscopy (FT-IR) after various immersion period of time in SBF solution. The electrochemical corrosion behavior of both the untreated and surface modified magnesium alloy specimens was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy. Quantum chemical calculations, Quantitative structure activity relationship were performed and the results are obtained.

Pitfalls with Electrochemical Impedance Spectroscopy and equivalent circuit models D.R. McCracken, G.A. McRae Mechanical and Aerospace Engineering, Carleton University, ON, Canada, K1S 5B6

Electrochemical impedance spectroscopy (EIS) is a standard tool used to characterize barrier coatings on metals. Electrical Equivalent Circuits (EEC) composed of linear elements, resistors, capacitors, inductors and constant phase elements are commonly used to interpret EIS spectra. These circuits are analogs rather than mechanistic models. They often do not represent the chemistry and physics of the sample being studied, but only mimic the frequency response. It is not always clear if these circuits provide anything more than lines through data. In this presentation, EIS will be used to categorize the failure of barrier layers on aluminum, and standard circuit curve fitting with its associated pitfalls will be shown. Coating failure results in pitting corrosion of the underlying aluminum. When this failure occurs, it is indicated within seconds by: positive phase angles; spikes in impedance and phase angle at low frequencies (< 1 Hz); and associated positive slopes in plots of impedance magnitude against frequency. The foil system can be insensitive to AC voltages, but very sensitive to applied DC voltages, which can turn corrosion on or off. There is no inductance involved in the process, although equivalent circuits containing an inductance can sometimes fit the data. These circuits do not account for secondary voltage sources associated with pitting, so that measured impedances can be wrong: the total current is known but not the voltage. Positive phase angles were always associated with active corrosion, and were postulated to arise from a rate determining chemical reaction’s slow response to reversal of voltage. In our foil experiments the half-life for the chemical reaction is about 3 seconds. To counteract these active occurrences, it is recommended that a cathodic DC bias be employed whenever EIS is used to probe the properties of a barrier layer on a metal.

Session H: Cathodic Protection

Electromagnetic Interference in Pipelines: the Influence of Conductivity of the Pipeline Contents David Boteler Natural Resources Canada

Electromagnetic interference in pipelines can occur because of telluric currents, stray currents from railways, and AC induction from nearby power lines. There are established techniques for estimations of the effects of this interference on pipe-to-soil potentials. One of them is to model the interference by representing the uniform parts of pipeline as electrical circuit and join them together for modelling of the whole pipeline network.

This modelling uses the series impedance along the pipeline steel and the parallel admittance to ground through

the pipeline coating, but typically ignores the electromagnetic properties of the contents of the pipeline. In this paper we examine the influence of the conductivity of the pipeline contents on the response of a typical pipeline to electromagnetic interference. Calculations are presented for pipelines with non-conducting contents (eg gas) and with conducting contents (eg seawater). The results show the extent of the change in pipe-to-soil potentials that is possible due to the conductivity of the pipeline contents.

DC Voltage Gradient Surveys for Pipeline Risk Management Daniel Fingas Corrosion Service Co., Ltd.

Using the DCVG survey technique, it is possible to locate coating damage on buried pipelines. The established theory behind the technique is explained and the limitations are discussed. The accepted classification guidelines, based on the “%IR”, are reviewed and the significance of the %IR is explained.

Two applications of the DCVG survey are presented. The first application is as part of an ECDA process to locate areas where there is contact between the pipeline and electrolyte and, therefore, where corrosion is possible. The second application is to enhance the data analysis and dig selection for in-line inspections by comparison with DCVG survey results.

Considerations for applying the DCVG technique to new construction projects to detect coating deficiencies, and particularly damage sustained during installation, are also presented.

Solid Oxide Fuel Cells for Remote Impressed Current Cathodic Protection Application Mike Brennan Acumentrics Corporation

The technical Presentation will include discussion of the following topics:

• The technology of SOFC Fuel Cells • System Reliability and Maintainability • Applications • How SOFCs compare against other methods of remote power • Wrap-up: What’s the next step?

Session I: Oil and Gas

Corrosion Growth Rate Management Plan considering Measurement Error Mona Abdolrazaghi Enbridge Pipelines Inc.

A corrosion growth rate (CGR) management plan provides beneficial information regarding monitoring the growth of corrosion defects over time and estimates the severity of CGR over line segments. Estimating the CGR value can assist in choosing the correct mitigation (repair, pressure reduction, ILI re-inspection interval) for the identified corrosion defects.

Several methodologies have been proposed to estimate the CGR. However, there is no guideline or standard regarding how to employ CGR information effectively. The intent of this paper is to provide a framework on implementing different CGR identification processes with real-life examples.

Since corrosion in-line inspection (ILI) measurements will contain measurement errors, calculating CGR based solely on them may not be accurate. The two main categories of CGR calculations, deterministic and probabilistic, can each be computed by accounting for the tool error. This paper focuses on measurement error in CGR

calculation. Three particular probabilistic CGR calculations are discussed: adding a tool tolerance distribution; the ratio of measurement error to tool error; and Bayesian estimation. The pros and cons of each methodology are discussed using a number of validation cases using real data for assorted CGR calculations. Probabilistic CGR methodology is based on filtering out the probability of meaningless negative growth rates. Bayesian CGR methodology discusses the effect of the Bayesian approach and refining the CGR estimate over a high number of iterations. All these methodologies assume a measurement error model. The challenge of using a probabilistic approach is identifying the actual CGR from data contaminated with measurement error.

This paper provides an insight into the calculation of CGR estimates, proper implementation of CGR data to mitigate corrosion in various real-life examples, and determining the health of a pipeline and estimating future inspection intervals.

Validating Metal Loss In-line Inspection using API 1163 and CEPA Guidance Document Yan Ping Li Enbridge Pipelines Inc

A process to validate metal loss in-line inspections (ILIs) is proposed by combining two different approaches; namely, API 1163 and CEPA Guidance Document. Addressing the gaps and strengths of both approaches is considered while developing the proposed process. The process adds a new dimension to the validation procedure by evaluating different corrosion morphologies, depth ranges, and proximity to long seam and girth weld. The proposed process is expected to support appropriate digs selection as part of the integrity management program.

API 1163 determines whether an ILI inspection meets claimed specifications by comparing ILI data with field measurements. For an individual anomaly, if the difference between field and ILI measurements is smaller than the combined field and ILI measurement tolerance, the anomaly is considered within tolerance. For an ILI data set, an upper bound estimate of the actual proportion of features that are within tolerance at a certain confidence level (usually 95%) is estimated with available field data. If the upper bound estimate is smaller than ILI vendor claimed sizing certainty, the ILI performance is worse than specified with certain confidence. Otherwise, the ILI performance meets its specification with certain confidence.

The CEPA guidance document provides a method to validate an ILI inspection by comparing it with previous ILI data and excavation data. The standard deviation of the depth difference between ILI and field data or different ILI inspections is compared with the acceptance criteria to determine whether the ILI inspection meets its claimed specification.

ASME PCC-2, 4.1 Compliant Composite Repairs Tammy Bomia NRI

Composite repair systems continue to gain popularity as a rehabilitation option for the oil and gas pipeline industries. In order to successful specify and install these systems, a greater understanding of the requirements set forth in the ASME PCC2, Article 4.1; Nonmetallic Composite Repair Systems: High Risk Applications, is crucial for successful design and long term service. Understanding the requirements of this document can provide additional confidence in using composite repair technology to maintain pipeline integrity in areas of corrosion or mechanical damage.

This paper will discuss key topics within the ASME PCC2, Article 4.1, including qualifying repair systems for use through physical Y; long term testing, design of repairs, allocation of responsibility between the manufacturer, installer &amp; asset owner, quality control, training and documentation requirements.

Session J: Corrosion Inhibitors

Corrosion Mitigation of X-60 type Carbon Steel in Petroleum Formation Water under Pressure of CO2

Bassam Sheriat Egyption Natural Gas Holding Company (Egas)

The aim of this research is to study the performance of typical gas and oilfield corrosion Inhibitors based on linoloeic acid (nontoxic to the environment) in controlling internal corrosion of X-60 carbon steel pipelines under high pressure of CO2. Potentiodynamic polarization and electrochemical impedance spectroscopy of (EIS) techniques were used to evaluate the efficiency of the prepared compounds as corrosion inhibitors at various doses (25, 50, 75, 100, 125 and 150 ppm). The results obtained from polarization measurements indicated that the selected inhibitors retard both cathodic and anodic reactions and act as mixed type inhibitors. EIS data revealed that, by increasing the inhibitor consecration both the inhibitor efficiency (IE %) and charge transfer resistance (Rt) are increased while, the electrochemical double layer capacitance (Cdl ) decreased. The high inhibition efficiencies were attributed to the simple blocking effect by adsorption of inhibitor molecules on the steel surface. The surface active properties of the synthesized surfactants wear determined from surface tension measurements at 25oC. The protective film formed on the carbon steel surface is studied by scanning electron microscope (SEM), and energy dispersive analysis of X-ray (EDX). The quantum chemistry calculations were carried out to study the molecular geometry and electronic structure of obtained derivatives. The energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital has been calculated using the theoretical computations to reflect the chemical reactivity and kinetic stability of compounds.

Experimental and Theoretical studies on newly Synthesized Photo-Cross-Linkable Chalcones for Inhibit Baskar Ramaganthan North-West University, South Africa.

Synthesis of different chalcone derivatives namely (E)-(1-(5-(4-(3-(4-methylphenyl)-3-oxoprop-1-enyl)phenoxy) pentyl)-1H-1,2,3-triazol-4-yl)methyl acrylate (CH-5), (E)-(1-(5-(4-(3-(4-methylphenyl)-3-oxoprop-1-enyl)phenoxy) hexyl)-1H-1,2,3-triazol-4-yl)methyl acrylate (CH-6) and (E)-(1-(5-(4-(3-(4-methylphenyl)-3-oxoprop-1-enyl) phenoxy)decyl)-1H-1,2,3-triazol-4-yl) methyl acrylate (CH-10) were characterized by Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) spectroscopic techniques. Photo-cross-linkable properties of chalcones were studied by UV-Visible spectroscopy. Electrochemical impedance measurements, Potentiodynamic polarization measurements and adsorption isotherms were evaluated for mild steel in acidic medium to calculate the corrosion inhibition efficiency of chalcones. The surface analysis of the mild steel in acidic medium was evaluated using Scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDX) analysis. The electrochemical measurements and surface analysis were revealed that the photocrosslinked chalcone derivatives have superior corrosion inhibition efficiency compared with the intact chalcone derivatives. Correlations were found between corrosion inhibition efficiency and some quantum chemical parameters such as the energy of the highest occupied molecular orbital (EHOMO), energy of lowest unoccupied molecular orbital (ELUMO) and HOMO–LUMO energy gap.

Corrosion Behavior of Aluminum Alloy in the Presence of Four Corrosion Inhibitors in Water-Ethylene Glycol Mixture Mohammad Asadikiya

Four types of corrosion inhibitors consisting of sodium diphosphate (Na2H2P2O7), sodium benzoate (NaC7H5O2), sodium chromate (Na2CrO4) and sodium tetraborate (Na2B4O7) were used to investigate the changes in the

corrosion behavior of aluminum alloy 3303 (UNS A93303) in water-ethylene glycol (C2H6O2) mixture. In the all tests, the temperature was 88°C and the solutions were circulated with the rate of 720 rpm. The effects of these four inhibitors on 3303 aluminum alloy which was coupled with five other metals consisting of mild steel, stainless steel, brass, copper and solder were studied. Thus, by comparing the measured polarization curves, the effects of each corrosion inhibitors were investigated. The results show that without any corrosion inhibitors, the water-ethylene glycol mixture causes pitting corrosion on the aluminum alloy. Also the results show that the aluminum alloy was passivated with sodium diphosphate and sodium chromate. Reduction in corrosion rate of aluminum, however, was occurred just in the existence of sodium diphosphate. The corrosion rate of aluminum alloy in the solutions without any corrosion inhibitors and with the existence of sodium diphosphate were 94 mpy and 86 mpy respectively.

Session K: Student Posters

Sulfide Induced Corrosion of Carbon Steel in Carbonate Buffered Aqueous Solutions Maxwell Goldman The University of Wester Ontario

External corrosion accounts for ~ 38% of structural integrity problems along the ~60,000 km of pipeline operated by TransCanada Pipelines (Calgary, AB). Corrosion generally occurs when pipeline coatings disbond exposing the carbon steel to groundwater and shielding the pipe from cathodic protection. Subsequently, pipeline corrosion will depend on the environment established at the failure site. In this project, the reactions occurring on carbon steel in neutral to alkaline simulated groundwaters are being studied electrochemically and in corrosion experiments.

Voltammetric and corrosion experiments are being performed on carbon steel in a carbonate buffered solutions containing concentrations of sulphide that range from 10-6 to 10-3M. Cyclic Voltammetry (CV) measurements yield information on the stages of reaction including Fe dissolution and oxide film formation and how they are influenced by the presence of sulphide. In corrosion experiments, the corrosion potential (Ecorr) and polarization resistance (RP) are being used to follow the evolution of the corrosion process with exposure time. The nature and morphology of film formation is being studied using Raman Spectroscopy, scanning electron microscopy (SEM) and Energy dispersive X-Ray Spectroscopy (EDX) on both the exposed surfaces and on Focused Ion Beam (FIB) cut cross sections. Presently, these studies are being conducted in solutions in the pH range 8 to 10.

In an alkaline environment (pH 10) and in the presence 10-6M Na2S predominant film formed is y-FeOOH. This film is known to be passive in character. However, as the pH decreases and the sulphide concentration is increased to 10-5 M, a thin film of FeS (mackinawite) becomes the dominant corrosion product. Under these conditions mackinawite is able to partially passivate the Fe surface at sulphide concentrations ≤10-4M. Pitting corrosion was observed at pH 9 and 10-4M Na2S. These pits produced large porous deposits at the corrosion site which FIB cross sections showed were up to ~0.5 μm deep. For sulphide concentrations &gt; 10-3M, pH 10 a thin mackinawite film with passive properties is formed and only minimal surface damage occurs. The final currents obtained in potentiostatic experiments were similar to those measured at sulphide concentrations lower than 10-3 M. When the pH is decreased to pH 9 and 8 the mackinawite film becomes non adherent and highly porous, and general corrosion spreads across the surface of the steel. The increase in the current measured in potentiostatic experiments is consistent with the presence of a porous film and the occurrence of more widespread corrosion.

Corrosion of Carbon Steel under Deep Geologic Disposal Conditions for Spent Nuclear Fuel Waste Shannon Hill The University of Western Ontario

The proposed disposal scenario for high level nuclear waste in Canada is emplacement within a sealed, deep geological repository located in either granitic rock or sedimentary clay. Disposal is based on a multi-barrier approach, with a primary barrier being a sealed container which could be either dual-walled with a copper shell over an inner carbon steel vessel, or (for a sedimentary clay repository) a single thick-walled carbon steel container. The corrosion performance of the single-walled container is being evaluated in long term corrosion studies of A516 Gr70 carbon steel in four solutions; 0.10 M NaCl, 4.77 M NaCl, 4.77 M NaCl with 0.10 M NaHCO3/ Na2CO3, and a simulated sedimentary clay groundwater with [Cl-] = 4.77 M.

Steel coupons are being exposed to these solutions in an anaerobic chamber and specimens periodically removed over a period of 12 months for examination using Raman and infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The distribution of corroded surface sites is being determined using image analysis techniques, and the depth of corrosion assessed through metallographic cross sections.

After exposure to the chloride solutions, corrosion was initially non-uniformly distributed with maghemite (γ-Fe2O3) the predominant corrosion product at locally corroded (pitted) sites. With time magnetite (Fe3O4) became the dominant corrosion product with the transition occurring more rapidly in the higher chloride (4.77 M) environment. The pits observed to form after short exposure times ( ~ 2 days) did not grow significantly over the longer exposure periods, suggesting their formation can be attributed to the removal (by galvanic coupling to the steel matrix) of the air-formed oxide initially present and to some corrosion caused by the presence of residual oxygen in the solutions.

In the carbonate-containing solution, Fe3O4, green rust chloride [Fe3(II)Fe(III)(OH)8][Cl•2H2O], and chukanovite [Fe2(CO3)(OH)2] (identified by FTIR) were observed. While the morphology did not change, an increase in intensity of the FTIR peaks in addition to the disappearance of the Fe3O4 and GR(Cl-) peaks with increased exposure time indicates the thickening of a dominantly Fe2(CO3)(OH)2 deposit. Examinations of metallographic cross sections are underway to confirm whether this is the case or not.

In the simulated groundwater, the steel became rapidly covered by gypsum (CaSO4•2H2O) and aragonite (CaCO3) precipitates, with the observation of Fe3O4 and green rust after longer exposure times confirming that these precipitates did not completely stifle corrosion. Removal of the CaSO4•2H2O and CaCO3 precipitates will allow for further analysis by Raman and SEM of the underlying corrosion processes at the steel surface.

These studies are being complemented by electrochemical studies (cyclic voltammetry, corrosion potential (ECORR), linear polarization resistance (RP) and electrochemical impedance spectroscopy (EIS)).

Effect of Friction Stir Welding on the Corrosion Fatigue Performance of Magnesium Alloy AZ31B-H24 Daniel Tapp McMaster University

Load-controlled fatigue experiments were conducted in both laboratory air and in a near-neutral salt fog environment to delineate the effect of friction stir welding on the atmospheric corrosion fatigue performance of magnesium alloy AZ31B-H24 sheet product. Compact tensile (CT) specimens were utilized to restrict the crack initiation to the metallurgical weld zone of interest. The CT samples were oriented such that the loading axis was perpendicular to the friction stir weld direction yet parallel to the rolling direction of the sheet product.

The fatigue performance of non-welded CT samples in both environments was included as the comparative

basis. Preliminary results have revealed that a significance reduction in the number of cycles to failure at each stress level tested in the near-neutral salt fog (0.05 wt.% NaCl) relative to laboratory air. This poster presentation will show the results of the corrosion fatigue experiments and attempt to forge links between the microstructure and the corrosion fatigue performance through examination of the fracture surfaces using electron microscopy techniques. The role of residual stress associated with friction stir welding on the corrosion fatigue performance will be evaluated by X-ray diffraction.

Characterization of Sulphide Films Formed on Copper in Aqueous Sulphide/ Chloride Solutions Taylor Martino Western University

Copper is the primary candidate material for the fabrication of nuclear fuel waste containers in Sweden, Finland and Canada primarily for its thermodynamic stability in the anoxic aqueous environments anticipated in geologic repositories. Microorganisms, abundant in the compacted clays surrounding the emplaced containers, will rapidly consume available oxygen leading to the rapid establishment of anoxic conditions at the waste container surface. Subsequently, the only potential oxidant for copper is sulphide produced either by the dissolution of sulphide minerals or by the action of sulphate reducing bacteria. The anticipated sulfide concentrations in a Swedish repository are in the range 10E−7 to 10E−4 mol/L, and container corrosion has been modeled by assuming it is controlled by the transport of this sulfide through the clay buffer to the copper container surface.

The primary goal of this study is to determine the mechanism of sulphide film formation on copper and how it is influenced by the presence of chloride ions. A series of cyclic voltammograms have been recorded on a disc electrode rotated at various angular rotation rates in Ar-purged solutions containing various concentrations of sulphide (10E-5–10E-3 mol/L) and chloride (0.1–5 mol/L). These experiments show that film growth is governed by electrochemical kinetics at low anodic potentials but switches to a mixture of SH- transport and chemical control at higher potentials. Three distinct types of film can be formed. The initially formed film grows rapidly via an ion (or associated defect) transport process. If this film remains coherent, the subsequent electrochemical film growth is slow (Type I). If the interfacial stresses lead to film fracture then film growth continues via the transport of copper ions through the fractured film leading to the formation of a much thicker deposit at the film/solution interface (Type II). Under high sulphide and mass transport conditions the formation of a partially passive film (Type III) is observed. FIB/SEM examinations are used to examine the morphology of the films. This project is funded by the Swedish Nuclear Fuel and Waste Management Company (SKB), Stockholm, Sweden.

On the Role of Grain Boundary Mechanical Property in the Intergranular Stress Corrosion Cracking Susceptibility of 310S Exposed in Supercritical Water Yinan Jiao McMaster

The goal of this study is to develop a methodology to quantify the degree of grain boundary mechanical property in degraded (thermally-treated/irradiated) Type 310S stainless steel in order to be used as a predictive ‘signature’ for assessing intergranular stress corrosion cracking (IGSCC) susceptibility in supercritical water (SCW). Samples of 310S stainless steel were solution annealed (1060°C for 1 h &#43; water quench), sensitized (650 °C for 100 h) to precipitate grain boundary carbides and thermally-treated (800 °C for 1000 h) to precipitate intra-grain and grain boundary carbides and sigma phase. Thermally-treated 310S materials will then irradiated using 3.4 MeV protons to 3 dpa. The intergranualr corrosion (IGC) susceptibility of the thermally-treated material was evaluated using: hardness/YS measurement, nano-indentation and nano-scratch tests. The susceptibility to IGSCC of the thermally-treated material was evaluated using slow strain rate testing (SSRT) in 25 MPa SCW at 500 °C with 8 ppm dissolved oxygen in an autoclave flow loop (200 mL/min.). This paper will present the results of our attempt to correlate the IG mechanical property with IGSCC susceptibility. The results will be discussed within the context of the role played by the degree of grain boundary hardening in the overall IGSCC mechanism.

Effect of Casting Techniques on the Corrosion Performance of AA7050 Darren Feenstra McMaster University

Experiments were conducted to characterize and compare the localized corrosion resistance of aluminum alloy AA7050 casted by the controlled diffusion solidification (CDS) against wrought AA7050. CDS is a casting technique that prevents hot tearing when casting AA7xxx alloys, by mixing two precursor melts at specific temperatures and compositions. This process avoids the problem of hot tearing by causing copious nucleation in the melt prior to solidification, reducing the amount of solute segregation and dendritic growth creating a consistently equiaxed microstructure.

Electrochemical potentiodynamic polarization experiments were complemented with light optical microscopy to characterize the corrosion performance. The effect of the CDS technique on the corrosion resistance was hypothesized by comparing the composition of the grain boundaries of the two variations of AA7050 using 3-D APT. Grain size, distribution were also compared. EBSD was used to compare grain orientation maps. SEM-EDS mapping was also conducted to identify and compare constituent intermetallic particles.

The Corrosion of Simulated Nuclear Fuel in Hydrogen Peroxide Solutions- Effects of Fission Products Ziyan Zhu Uwo

The scenario for the disposal of spent nuclear fuel is to seal it in metallic containers and bury it in a deep geologic repository. If these containers were to fail, the fuel would be exposed to groundwater and would corrode by reaction with radiolytic oxidants, in particular H2O2 produced by radiation decay within the fuel. Besides causing fuel corrosion H2O2can decompose to H2O and the less aggressive oxidant, O2. The goal of this project is to determine the balance between decomposition and fuel corrosion.

The anodic dissolution and decomposition reactions are being studied electrochemically using SIMFUEL (simulated spent fuel) in 0.1 M NaCl solutions containing various concentrations of carbonate/bicarbonate with a primary emphasis on determining the influence of fission product dopants within the fuel. Of particular interest are the noble metal particles which can act as catalytic electrodes within the fuel. Since HCO3 CO3 2- is a strong complexant of the fuel corrosion product, UO22&#43 it is expected to enhance fuel corrosion at the expense of H2O2decomposition. The amount of UO22&#43 dissolved is being measured using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and converted to a charge using Faraday’s law. The total amount of fuel corrosion and H2O2 decomposition can be determined by integrating the measured electrochemical current to determine the total charge consumed.

At low applied potentials (250 mV (vs SCE)), 30~35 % of the anodic current was due to the oxidation of UO2. At higher applied potentials (400 mV (vs. SCE)), the formation of a UO2(CO3) surface layer inhibited the oxidation of the UO2 surface and 90% of the anodic current was used in the oxidation of H2O2. By comparing the behaviour on SIMFUEL electrodes with/without noble metal particles it was shown that the majority of H2O2 oxidation was occurring on the particles. High carbonate concentrations accelerated the dissolution reaction UO2 (CO3)→UO2(CO3)22-, especially at concentrations 50 mM. This caused an increase in the oxidation of H2O2 since it lead to dissolution of UO2(CO3) layer and exposure of the underlying catalytic UIVUV surface, which was then available for H2O2 oxidation reaction.

Galvanic Coupling of Copper and Carbon Steel: An Investigation for Used Nuclear Fuel Containers Thalia Standish Western University

Within the multi-barrier system proposed for the disposal of nuclear fuel wastes, the primary engineered barrier is the sealed metallic waste container. The present Canadian container design involves a copper-coated carbon steel vessel, with a coating thickness of a few millimetres. When emplaced in a deep geologic repository, the two most likely corrosion processes are reaction with sulphides present in the groundwater and galvanic corrosion of the steel at a fabrication defect in the copper coating. This project deals with the second of these two processes.

If the lifetime of copper-coated carbon steel containers is to be assessed, it is necessary to evaluate the impact of the galvanic corrosion process. This could occur if both the copper coating and the steel vessel were exposed to groundwater, when accelerated corrosion of the steel could increase the possibility of container failure, either through corrosion propagation through the steel wall or de-adhesion of the copper coating from the steel.

This scenario is being investigated by simulating a defect in the copper coating by drilling a small hole (380 to 500 µm in diameter) through the coating to the steel substrate. The corrosion process is being followed electrochemically in 3 mol/L NaCl solutions by monitoring the corrosion potential and periodically recording the polarization resistance using the linear polarization technique. Experiments are being conducted in solutions containing various concentrations of dissolved oxygen. The composition and morphology of the corrosion products are being determined using scanning electron microscopy (SEM), energy dispersive X-ray analyses (EDX) and Raman spectroscopy. The evolution of corrosion damage in the steel and at the coating/steel interface is being imaged usingx-ray micro-computed tomography (micro-CT).

Results to date from short term experiments (24 hours to 71 days exposure) show that galvanically accelerated corrosion of the steel does occur in oxygenated solutions and that the behaviour observed is dependent on the dissolved oxygen concentration in the solution. The corrosion behaviour also differs depending on the mode of formation of the coating. Cold sprayed specimens exhibited corrosion propagation along the interface between the copper and the steel, while electrodeposited coatings did not show such interfacial corrosion. This suggests that electrodeposition produces a more adherent coating than the cold spray procedure.

Oxide Scale Stability of High-Cr Containing Alloy 33: Static Autoclave vs. Flow Loop Test Shooka Mahboubi McMaster University

In the current research, the oxide scale stability of high Cr-containing austenitic stainless steel, namely Alloy 33 (33.4 wt% Cr) was studied after exposure in supercritical water (SCW). Furthermore, the effect of SCW flow rate and dissolved oxygen on the oxide scale structure and morphology was examined by means of gravimetric measurements and electron microscopy techniques. Coupons were exposed in two separate SCW conditions for 500 h: (i) static autoclave containing degassed SCW, and (ii) (200 ml/min) SCW flow loop with 8 ppm dissolved oxygen where in both cases SCW pressure and temperature was 25 MPa and 550 °C respectively.

Scanning Electron Microscopy (SEM) was used for plan view imaging of the coupons after exposure. Scanning Transmission Electron Microscopy (STEM) along with Energy Dispersive Spectroscopy (EDS) was used on thin foil TEM specimens prepared by Focused Ion Beam (FIB) milling for imaging, qualitative and semi quantitative analysis of the scale/substrate interface. Selected Area Diffraction (SAD) analysis and Electron Energy Loss Spectroscopy (EELS) were conducted for characterizing the oxide scales. In addition, X-ray Photoelectron Spectroscopy (XPS) was preformed to detect any trace of hydroxide in the oxide scales that could be related to further oxide scale volatization. STEM results revealed that the oxide scale formed on Alloy 33 was Cr2O3 and XPS results showed the presence of less than 2 at% Fe along with Cr-hydroxide in the oxide scale. On the other hand, STEM analysis on the oxide scale formed on Alloy 33 after exposure in the flow loop showed that the oxide scale is (Cr,Fe)2O3

where considerable amount of Fe-oxides were dissolved in the Cr2O3 layer. XPS analysis also confirmed the presence of (Cr,Fe)2O3 with no trace of Cr-hydroxide. Also in both cases, Ni-hydroxide was detected by XPS technique. Descaling procedure showed that Alloy 33 exposed in the static autoclave exhibited a lower weight loss than that exposed in the SCW flow loop. The manner in which the Cr-rich layer formed on Alloy 33 after exposure in the static autoclave is more protective than that formed after exposure in the flow loop is being examined within the context of diffusion process and Cr2O3 volatization rate.

Radiolytic Corrosion of Copper Nuclear Waste Containers Joseph Turnbull University of Western Ontario

The present management scenario for the permanent disposal of high level nuclear waste in Canada is to seal it in metallic containers and bury it in a deep stable geologic repository. For thick-walled containers radiation fields on the outside of the container would have a negligible influence on container corrosion. To overcome fabrication issues and to reduce costs, steel containers with a thin outer copper coating are being contemplated making a reassessment of the influence of gamma radiation on container corrosion a potential licensing requirement.

A combination of radiolysis calculations and electrochemical/corrosion experiments is underway in the key environments anticipated in the early stages of disposal when radiation fields are significant; aerated vapour conditions and anoxic saturated conditions. The ultimate goal is to develop a model to integrate the damage sustained in each period, and to assess the total damage expected over the period when gamma radiation fields are significant.

HNO3 will be one of the most influential radiolytic oxidants in the aerated vapour burial phase as it will concentrate in the condensed droplets on the canister exterior. Copper electrodes are exposed to small solution volumes in a micro cell to simulate these droplets. Substantial dissolution is observed regardless of [HNO3]. The corrosion proceeds as a three step process involving the dissolution of copper followed by the production of Cu2O and CuO on the electrode surface. The confines of the micro cell limit diffusion processes and allow for the redeposition of the dissolved Cu43; Cu2&43 as Cu2O and CuO. Surface analysis reveals cubic Cu2O crystals varying in size depending inversely on the [HNO3]. CuO is not visually present but its presence is confirmed by Raman spectroscopy. The surface of the copper electrodes are continuing to be analyzed to gain more insight into the mechanism of this corrosion process.

The Influence of Cooling Rate on the Corrosion Behaviour of a Wedge Cast Mg ZEK100 Alloy Wilfred Binns Western University

It is well known that the corrosion of Mg alloys is dictated by the galvanic coupling of secondary microstructures to the α-Mg matrix. A wide array of alloying elements have been investigated and identified as harmful, inert or beneficial from a corrosion perspective. However, the influence of secondary microstructure distribution, size and shape, which can be tailored by altering casting procedures, has not been interrogated as extensively. The goal of this study is to examine the effect of different microstructure sizes, shapes and distributions on the corrosion behaviour of the Mg ZEK100 alloy by changing the cooling rate of the alloy.

Differences in cooling were achieved by wedge casting the ZEK100 alloy. Time-temperature curves show that a gradient in the cooling was achieved along the center line of the cast with the thin portions exhibiting the fastest cooling. The wedge was then sectioned in 0.5 cm increments along the center line for the first 2 cm of the narrow portion and 1 cm increments in the thick portion of the wedge. The resultant microstructure was examined by optical microscopy and with EDX elemental analysis with an SEM. All sections of the wedge were shown to contain what is likely Mg7Zn3RE (T-phase) and Zr-rich intermetallic particles. Specimens experiencing faster cooling exhibited much smaller grain sizes than specimens taken from the thickest portion of the wedge. Furthermore, Zn was shown to localize in grain boundaries for slowly cooled specimens while remaining evenly

distributed throughout specimens experiencing fast cooling. Samples were then subjected to various chloride containing environments and studied with various microscopic and electrochemical techniques.

Samples from various portions of the wedge were polished and pre-mapped with scanning electron microscopy (SEM) to identify an area of interest (aoi) containing different microstructural features. The samples are being immersed for various times and the aoi revisited by SEM and Confocal Laser Scanning Microscopy (CLSM). Experiments completed to date show that damage occurred intergranularly adjacent to T-phase precipitates, most likely as a consequence of the galvanic couple existing between the α-Mg and the T-phase. Furthermore, this damage morphology appears more extensive for slowly cooled specimens. A second mode of damage is occurring inside the grain boundary in small pit-like formations which occur irrespective of the rate of cooling of the wedge. Electrochemical measurements (ECORR, PDP and EIS) are revealing similar behaviour for specimens taken from different portions of the wedge.

Pitting Behavior of High Strength Pipeline Steel in Aerated NaCl Solutions Yafei Wang China

The pitting behavior of X80 high strength steel in NaCl solutions was studied systematically for the first time. Electrochemical methods including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS),and electrochemical current noise (ECN), combined with microscopic observation including scanning electron microscope (SEM), confocal laser scanning microscope (CLSM) were used to characterize the pitting corrosion. It was found that the X80 steel is easily susceptible to pitting corrosion in aerated chloride containing solutions with pH in a wide range (4–12.5), at room temperature. Film growth, has great influence on the cathodic reaction by affecting oxygen diffusion process. Unique large pit morphology due to corrosion in neutral/acidic solutions with 0.05 mol/L NaCl was observed, and the corresponding mechanism for the horizontal propagation of pit is proposed based on the results of microscopic images. It was also found that current transients are more related with the pit initiation process than the pit propagation process, by comparing the amplitude of current transients with the pit sizes observed through microscope. Computer simulation of ECN reveals that cathodic process and overlapping of current transients have great influence on the current signal, which makes it an unreliable method to characterize pitting quantitatively.

Effect of pH and Gamma Radiation on Corrosion and Oxide Film Formation on Alloy 800 Mojtaba Momeni

Steel and nickel alloys are common system components of power plants; In nuclear power plants, corrosion and corrosion product transport are important safety and operational concerns. Corrosion products can be neutron activated if they enter a reactor core and then they become a potential radiological hazard. Corrosion kinetics depend on the metallurgical properties of the corroding alloy and the aqueous redox conditions. The type of oxide that can be formed strongly depends on the aqueous redox environment and the surface oxide that is formed determines long-term corrosion behaviour. Water radiolysis creates transient reactive redox species which alter the local water redox chemistry and thereby influx the corrosion process.

In this work, we have examined the corrosion of Alloy 800, one of the Fe-Cr-Ni alloys that are widely used as tubing material in the steam generators of power plants. The impact of water radiolysis was investigated by looking at coupon corrosion with and without a gamma radiation field present, at different pHs. The nature and extent of the corrosion was measured using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES) and inductive coupled plasma mass spectroscopy (ICP- MS). In the pH range where the solubilities of metal cations are high, the oxide film that is formed is thin and the rate of metal ion dissolution is relatively high. However, in the range of pH where the solubilities are low, most of the metal cations created by corrosion participate in growing the oxide layer. The presence of gamma radiation increases the corrosion potential in the system and this leads to the formation of oxides containing metal ions in higher oxidation states.