welding technology - government of prince edward · pdf filegas tungsten arc welding is a...

2010

Prince Edward Island Department of Education

and Early Childhood Development

P.O. Box 2000, Charlottetown

Prince Edward Island

Canada, C1A 7N8

Tel. (902) 368-4600

Fax. (902) 368-4622

http://www.gov.pe.ca/eecd/

1

Welding TechnologyGas Tungsten Arc Welding (GTAW) (WEL801E)Course Description Gas tungsten arc welding is a precise method of welding various types of metal. GTAW is a process widely used in the welding fabrication industry. During this course students will learn to identify, describe, and safely use the equipment and tools required to perform GTAW welds in a variety of positions on various types of metal.

SCO - Identifi es the Specifi c Curriculum Outcome (SCO)

Column 1SCO - DelineationsDescribes what the students are expected to know, be able to do, and value in order to achieve the SCO.The teacher is responsible for the planning and facilitation of learning as well as the assessment of each SCO - Delineation.

Column 2Student Knowledge, Abilities and Competencies Provides clarity to the SCO by describing the knowledge, abilities, and competencies that the students develop. This column is designed to indicate the depth and breadth of the SCO. It is not necessary to use all of these suggestions or that all of the students be engaged in the same learning activity.

Column 3Teacher Lessons / DemonstrationsProvides suggestions for developing and delivering the content for student learning.

Student Activities / AssessmentsProvides suggestions for creating meaningful activities to allow the student to achieve the SCO.

Column 4ResourcesLists a variety of resources that support the teaching and learning related to the SCO. These resources are suggested to support the teacher in developing an effective instructional package for delivery to the students.

Classroom Component—Suggested time: 19 hours This component of the curriculum is required to teach the knowledge and skills associated with the learning outcomes of the curriculum.

Skill Development Component—Suggested time: 91 hours This component of the curriculum is required by the student to apply the knowledge and develop the skills related to the learning outcomes of the curriculum.

CAREER AND TECHNICAL EDUCATION CURRICULUM2

CURRICULUM OUTCOMES

Module 1: Materials Handling (~10 hours Classroom Component)

28. Students will be able to apply safe procedures for handling materials.

Students will be expected to28.1 identify safe procedures for handling and storing materials28.2 determine weight and centre of gravity of loads28.3 describe the effect that sling angles have on safe lifting28.4 identify the load limits of commonly used wire rope slings and synthetic slings28.5 describe the causes and effects of shock loading on rigging28.6 identify relevant Occupational Health and Safety Regulations28.7 identify and use hand signals for crane operations28.8 describe safe procedures for lifting, hoisting, and moving loads28.9 describe the purpose and use of knots28.10 describe the care and use of wire rope, synthetic rope, and chains28.11 describe the correct use of plate clamps28.12 describe the correct procedure for applying cable clips

Module 2: Introduction to GTAW Process (~2 hours Classroom Component)

29. Students will be able to apply safe work practices and procedures when using GTAW.

Students will be expected to29.1 describe the GTAW process and applications29.2 explain the advantages and disadvantages of the GTAW process29.3 explain hazards and protective measures associated with GTAW29.4 identify the basic components of a GTAW work station29.5 describe types of GTAW power sources29.6 identify welding currents used in GTAW (a) AC current (b) DC current (c) High frequency current29.7 describe the torch assembly29.8 describe gas regulators and fl owmeters

CURRICULUM OUTCOMES

CAREER AND TECHNICAL EDUCATION CURRICULUM 3

Module 3: GTAW Electrodes, Filler Metals, and Shielding Gases (~4 hours Classroom Component)

30. Students will be able to select GTAW electrodes, fi ller metals, and gases.

Students will be expected to30.1 identify the function of the electrode in GTAW30.2 identify electrodes by AWS designations and explain their applications30.3 explain and demonstrate the care and preparation of electrodes30.4 identify the function of the fi ller metals in GTAW30.5 identify fi ller metals by AWS and CSA designations and explain their applications30.6 identify types and purpose of consumable inserts30.7 explain the care and handling of fi ller metals30.8 describe the types and applications of shielding gases used in GTAW30.9 describe the advantages and disadvantages of various types of shielding gases

Module 4: GTAW Equipment Maintenance and Troubleshooting (~3 hours Classroom Component)

31. Students will be able to maintain and troubleshoot GTAW equipment.

Students will be expected to31.1 diagnose power source output current problems and demonstrate corrective measures31.2 diagnose GTAW torch and cable assembly problems and demonstrate corrective measures31.3 explain the care and handling of GTAW equipment and components31.4 diagnose shielding gas coverage problems and demonstrate corrective measures

Module 5: GTAW Welds on Mild Steel (~18 of 91 hours Skill Development Component)

32. Students will be able to place stringer beads in the fl at position, prepare joints for GTAW, and perform welds in the 1F, 2F, and 3F positions.

Students will be expected to32.1 strike an arc using the touch start or lift start and high frequency methods32.2 demonstrate the ability to weld stringer beads in the fl at position on mild steel gauge plate32.3 prepare joints for GTAW on mild steel gauge plate32.4 demonstrate the ability to weld fi llet welds in the 1F position on mild steel gauge plate32.5 demonstrate the ability to weld fi llet welds in the 2F position on mild steel gauge plate32.6 demonstrate the ability to weld fi llet welds in the 3F position on mild steel gauge plate

5CAREER AND TECHNICAL EDUCATION CURRICULUM

WEL801E - GAS TUNGSTEN ARC WELDING (GTAW)

Materials Handling (~10 hours Classroom Component)

Introduction Handling materials of various sizes, shapes, and weights is a common practice in the welding trade. An apprentice must be aware of all rules and regulations governing the handing of materials and be able to follow procedures to ensure their own safety and the safety of those working with them.

28. Students will be able to apply safe procedures for handling materials.

Assessment

Strategies

Resources Alberta Module 120101j, Materials HandlingNational Occupational Analysis (NOA), Human Resources and Skills Development Canada (HRSDC): Occupational Analyses Series - WelderStudentsAchieve (http://sas.edu.pe.ca)

Students will be expected to28.1 identify safe procedures for handling and storing materials28.2 determine weight and centre of gravity of loads28.3 describe the effect that sling angles have on safe lifting28.4 identify the load limits of commonly used wire rope slings and synthetic slings28.5 describe the causes and effects of shock loading on rigging28.6 identify relevant Occupational Health and Safety Regulations28.7 identify and use hand signals for crane operations28.8 describe safe procedures for lifting, hoisting, and moving loads28.9 describe the purpose and use of knots28.10 describe the care and use of wire rope, synthetic rope, and chains28.11 describe the correct use of plate clamps28.12 describe the correct procedure for applying cable clips

Specifi c

Curriculum

Outcome

SCO - Delineations

Paper/PencilSelf/Peer-AssessmentsSkills PerformanceTeacher ObservationCareer Portfolio

SCO - Delineations Student Knowledge, Abilities, and Competencies

Students will be expected to

Materials Handling (~10 hours Classroom Component) SCO 28. Students will be able to apply safe procedures for handling materials.

WEL801E - GAS TUNGSTEN ARC WELDING (GTAW) - MODULE 1


28.1 identify safe procedures for handling and storing materials

28.2 determine weight and centre of gravity of loads

28.3 describe the effect that sling angles have on safe lifting

Topic: General Safety• Demonstrate an uderstanding of the standard personal protective equipment (PPE) required in the welding trade: - head protection - eye protection - ear protection - foot protection - limb and body protection • Demonstrate an ability to maintain a clean work environment.• Describe proper procedures for lifting and carrying loads.• Demonstrate an ability to follow lifting and carrying procedures.• Demonstrate an ability to store materials and supplies in a safe manner.

Topic: Weight• Locate lifting and rigging information.• Calculate the weight of an object to be lifted.• Defi ne “centre of gravity”.• Describe the effect of lifting an unstable load when the centre of gravity is not located directly below the hook.• Demonstrate an understanding of proper lifting and hoisting procedures.

Topic: Sling Angle• Defi ne “sling angle”.• Describe the rated capacity of a sling.• Describe the effect that sling angle has on the weight distribution across the legs.• Demonstrate knowledge of the sling stress formula.• Calculate the sling stress and determine the appropriate slings required to lift loads.

7

Teacher Lessons / Demonstrations Resources

CAREER AND TECHNICAL EDUCATION CURRICULUM



Topic: General Safety• Review safety practices for the welding facility.• Have on display examples of all of the PPE that welders are expected to wear.• Review emergency exit plans.

Topic: Weight • Create visuals (overheads or slideshow) of images in the ILM to explain centre of gravity.

Topic: Sling Angle• Create visuals (overheads or slideshow) of images in the ILM to explain sling angle.

Numeracy• Develop a math-enhanced lesson on calculating the weight of structural shapes.• Develop a math-enhanced lesson on determining the amount of tension on a sling.• Refer to “Fractions” module (WEL701A) for an example of a math- enhanced lesson.

Student Activities / Assessments

• Determine the centre of gravity for structural shapes.• Practise safe work habits and proper housekeeping while working on shop projects.

Literacy• Free Writing: Use as a pre-reading strategy. Write for 3 min. on experiences you have had related to general safety.

Numeracy• Calculate the weight of structural shapes.• Calculate the amount of tension on a sling.

Texts / Teacher ResourcesAlberta Module 120101jMaterials Handlingpp. 2-9

Software / DatabasesNOA, HRSDC: Occupational Analyses Series - Welder

StudentsAchieve (SAS)






28.4 identify the load limits of commonly used wire rope slings and synthetic slings

28.5 describe the causes and effects of shock loading on rigging

28.6 identify relevant Occupational Health and Safety Regulations

Topic: Slings• Describe advantages of wire rope slings.• Defi ne “working load limit”.• Calculate the working load limit of a wire rope.• Describe the advantages of synthetic slings.• Identify the confi gurations of synthetic web slings.• Demonstrtate an understanding of manufacturers’ specifi cations for web slings.

Topic: Shock Loading• Describe the actual working load of a wire rope.• Defi ne “shock loading”.• Describe how to avoid shock loading.

Topic: Occupational Health and Safety• Reference sections of the P.E.I. Occupational Health and Safety Act that apply to rigging equipment.• Interpret Occupational Health and Safety Regulations.

9





Topic: Slings• Have on display examples of a variety of wire rope and synthetic slings.• Demonstrate how to read and interpret sling manufacturers’ tables and charts related to working load limits of wire ropes.

Topic: Shock Loading• Discuss the ways to avoid shock loading.

Topic: Occupational Health and Safety• Review the content in the ILM and share with students the P.E.I. Occupational Health and Safety Regulations related to rigging.

Numeracy• Develop a math-enhanced lesson related to calculating the working load limit of wire ropes.


• Component ID: Identify a variety of slings and wire ropes.• Select the appropriate sling or wire rope for lifting operations.

Literacy• Say Something (p.13 of Materials Handling ILM): Take time to model the strategy with a student or colleague and review the rules that will make for a successful Say Something. It is a good idea to post these rules so everyone can see them and be reminded of them during the activity: - With your partner, decide who will say something fi rst. - When you say something, you should make a prediction, ask a question, clarify something you had misunderstood, or make a connection. - If you cannot do one or more of the above things, then you need to reread.









28.7 identify and use hand signals for crane operations

Topic: Hand Signals• Describe the role of the signal person.• Demonstrate an understanding of common hand signals.

Topic: Lifting, Hoisting and Moving• Defi ne “softeners” and describe their function.• Describe the types of stress and abuse that are applied to slings.• Demonstrate an ability to perform visual inspections of rope and slings.• Describe the function of the tag line.• Describe factors that can cause an uneven loading on sling legs.• Identify the following sling arrangements: - single vertical hitch - bridal hitch (two and three leg) - single basket hitch - double basket hitch - double wrap basket hitch - single choker hitch - double choker hitch - double wrap choker hitch• Describe the function of spreader beams.• State the importance of levelling a crane.• Describe procedures for levelling a crane• Describe factors that affect the lifting of any load.• Defi ne “load radius defl ection”.• Describe precautions to follow when hoisting and carrying a load.

Topic: Knots• Defi ne “knot”, “bend”, “hitch” and “splice”.• Describe the effect that knots, bends, hitches, and splices have on rope strength.• Demonstrate an understanding of the purpose and function of each of the knots, bends, hitches, and splices listed below: - bowline, bowline on a bight, running bowline, self-centring bowline - fi gure of eight (or fi gure eight) - clove hitch, round turn and two half-hitches - timber hitch - sheet bend, carrick bend - cat’s-paw• Demonstrate an ability to tie each of the knots, bends, hitches, and splices listed above.

28.9 describe the purpose and use of knots

28.8 describe safe procedures for lifting, hoisting, and moving loads

11





Topic: Hand Signals• Create for display in the welding facility a visual of the hand signals for crane operation.

Topic: Lifting, Hoisting, and Moving• Review general safety rules regarding the hoisting and lifting of items in the welding facility.• Demonstrate the application of softeners.• Demonstrate the application of the various sling arrangements.• Create a slideshow to highlight the various types of sling arrangements.• Create a slideshow to help describe the process of levelling a crane.

Topic: Knots• Create visuals from the ILM (overheads or slideshow) to identify the difference between knots, bends, hitches, and splices.• Demonstrate how to tie each of the knots, bends, hitches, and splices listed in column 2.

Literacy• Anticipation Guide: Use as a pre-reading strategy. Develop questions around the safe application and purpose of common knots, bends, hitches, and splices

CBL• Arrange for students to visit an industry where numerous hoisting, lifting and jacking operations are performed (e.g., Georgetown Shipyard). • Arrange for students to visit a work site that involves the use of a crane and have them witness a real application of hand signals.• Arrange for a local crane operator to bring a crane to the school so students can use hand signals to direct the crane through a series of movements.


• Role-play sets of crane operations with students as a class and in small groups.• Practise hoisting and lifting a load using a variety of sling arrangements and using softeners when necessary.• Label diagrams related to load radius.• Tie each of the knots, bends, hitches, and splices listed in column 2.• Use the correct knots, bends, hitches, and splices when handing materials in the shop

Literacy• Free Writing: Use as a pre-reading strategy. Have students write for 3 min. on a experience you had in which you had to rely on a rope or a knot to perform a task.









28.10 describe the proper care and use of wire rope, synthetic rope, and chains

28.11 describe the correct use of plate clamps

28.12 describe the correct procedure for applying cable clips

Topic: Care of Rope and Chains• Explain how a wire rope is constructed.• Explain the difference between an independent wire rope core and a fi bre core.• Defi ne “lay”.• Defi ne “lay length”.• Describe the construction of a right lay regular lay wire rope.• Explain the difference between regular lay and lang lay rope.• Interpret wire rope classifi cation tables.• Measure the size of a wire rope.• Defi ne seizing and describe its function.• Describe precautions to take when installing new wire rope.• Describe the advantages of synthetic rope over natural fi bre rope.• Demonstrate an understanding of the properties and uses of common ropes.• Describe factors that can reduce the breaking strength of a rope.• State safety factors to consider when lifting objects.• State safety factors to consider when lifting people.• Demonstrate an understanding of the advantages and disadvantages of lifting and hoisting using chains.• Identify grade 8 alloy (grade T) chain.• Describe the process of heat treating.• Demonstrate an ability to perform visual inspections of chains. Topic: Plate Clamps and Cable Clips• Describe the function of plate clamps.• Describe how to ensure the proper function of the plate clamps.

• Describe the function of wire rope clips.• Identify the two main types of wire rope clips.• Demonstrate the abililty to correctly install both types of wire rope clips.• Interpret manufacturers specifi cations on the use and installation of wire rope clips.

13





Topic: Care of Rope and Chains• Have on hand samples of right and left lay and right and left lang lay ropes for students to inspect.• Demonstrate how to seize a wire rope.• Demonstrate proper handling of wire rope.• Demonstrate the proper method of inspecting a chain.

Topic: Plate Clamps and Cable Clips• Demonstrate the application of plate clamps and cable clips.• Demonstrate the proper method of inspecting plate clamps and cable clips.


• Seize wire ropes.• Set up an inspection schedule for chains, wire ropes, plate clamps and cable clips used in the welding facility.• Replace a worn or damaged link in a chain.• Use plate clamps and cable clips when necessary while performing hoisting and lifting operations.




14 CAREER AND TECHNICAL EDUCATION CURRICULUM




Introduction to GTAW Process (~2 hours Classroom Component)

Introduction GTAW is a welding process which is used on a variety of metals where the utmost in weld quality is desired. Prior to performing a weld, an apprentice is required to select the specifi ed welding process for the job. Being familiar with GTAW and the consumables used with it will allow the apprentice to make appropriate choices.

29. Students will be able to apply safe work practices and procedures when using GTAW.

Assessment

Strategies

Resources Alberta Module 120202a, Introduction to GTAW ProcessNational Occupational Analysis (NOA), Human Resources and Skills Development Canada (HRSDC): Occupational Analyses Series - WelderStudentsAchieve (http://sas.edu.pe.ca)

Students will be expected to29.1 describe the GTAW process and applications29.2 explain the advantages and disadvantages of the GTAW process29.3 explain hazards and protective measures associated with GTAW29.4 identify the basic components of a GTAW work station29.5 describe types of GTAW power sources29.6 identify welding currents used in GTAW (a) AC current (b) DC current (c) high frequency current29.7 describe the torch assembly29.8 describe gas regulators and fl owmeters

Specifi c

Curriculum

Outcome

SCO - Delineations




Introduction to GTAW Process (~2 hours Classroom Component)SCO 29. Students will be able to apply safe work practices and procedures when using GTAW.



29.1 describe the GTAW process and applications

29.2 explain the advantages and disadvantages of the GTAW process

Topic: GTAW Process• Describe the GTAW process.• State applications of GTAW.• Describe the GTAW spot welding process.• State advantages and disadvantages of GTAW spot welding.• Describe hot and cold wire GTAW.• State advantages and disadvantages of hot and cold wire GTAW.

Topic: Hazards • Apply and describe safety measures to be taken with GTAW in reference to: - electrical shock - eye, face, and hearing protection (PPE) - fi re prevention - ventilation.

29.3 explain hazards and protective measures associated with GTAW

17






Topic: GTAW Process• Discuss the GTAW process, its application, and its advantages and disadvantages.

Topic: Hazards• Review the general safety regulations for the welding facility.• Demonstrate the application of the PPE required for GTAW.• Review fi re safety regulations for the welding facility.

LiteracyAnticipation Guide: Use as a pre-reading strategy. Allow students to make assumptions about the GTAW process based on what they already know about other welding processes.

LiteracySummarizing: Use as a post-reading strategy. Use a graphic organizer similar to the example to help illustrate the advantages and disadvantages of GTAW.

• Label diagrams of the GTAW process.

Compare and Contrast: Use as a post-reading strategy. Compare the process of GTAW to other welding processes (SMAW, GMAW, FCAW, OAW).

Texts / Teacher ResourcesAlberta Module 120102aIntroduction to GTAW Processpp. 2-10








29.4 identify the basic components of a GTAW work station

29.5 describe types of GTAW power sources

Topic: GTAW Outfi t and Power Sources• Identify the components of a GTAW work station.• Describe optional accessories that may be part of the GTAW work station.• Describe the process of pulsed GTAW and discuss its advantages.

• Describe factors that affect the type of power source required.• Describe the types of power sources available.• Defi ne “drooping”.• State the classifi cations of power sources.• Describe the features and controls built into a full function GTAW power source.

Topic: Welding Currents• Defi ne “amperage” and “voltage”.• State the welding currents used for GTAW.• Describe the resulting welding characteristics unique to each current type and polarity.• Describe the function and process of each of the following welding currents: - direct current electrode negative (DCEN) - direct current electrode positive (DCEP) - alternating current• Defi ne “arc rectifi cation”.• Defi ne “DC component”.• List features that help with arc starting and arc stability.• Describe the principles of operation and discuss the advantages and disadvantages of the following: - high-frequency current - high voltage injection - AC square wave output - AC unbalanced and balanced wave control• Identify proper welding current for a variety of metals.

29.6 identify welding currents used in GTAW: (a) AC Current (b) DC Current (c) High Frequency Current

19





Topic: GTAW Outfi t and Power Sources• Display all the components of a GTAW outfi t.• Demonstrate how to set the power source to perform GTAW welds.

Topic: Welding Currents• Create a slideshow of the graphics from the ILM to help illustrate the effects of welding current.

LiteracyMaterials related to outcome 29.6 (pp. 20-27) in this module may be diffi cult for students to read. Help students understand how to read the text by modelling reading strategies.

• Think Aloud and Say Something: Use as during-reading strategies. Take time when doing the Think Aloud to refl ect on how it is you yourself make meaning when reading challenging trade-related text, and how you relate the topic to prior topics covered (e.g., SMAW and GMAW equipment). Take time to model the Say Something strategy with a student or colleague and review the rules that will make for a successful activity. It is a good idea to post these rules so everyone can see them and be reminded of them during the activity: - With your partner, decide who will say something fi rst. - When you say something, you should make a prediction, ask a question, clarify something you had misunderstood, or make a connection. - If you cannot do one or more of the above things, then you need to reread.









29.7 describe the torch assembly

29.8 describe gas regulators and fl owmeters

Topic: Torches• Describe the characteristics of both air-cooled and water-cooled torches.• Describe how GTAW torches are rated.• Identify the components of both an air-cooled and water-cooled torch.• Describe the function of each of the following components: - torch cap - torch body - collet body and electrode collet - gas nozzles - gas lenses• Assemble a GTAW torch with the correct equipment to perform a weld.

Topic: Regulators and Flowmeters• Describe the function of a regulator.• Describe the function of a fl owmeter.• Discuss points to consider when selecting a regulator and/or fl owmeter.• Describe the function and characteristics of shielding gas hoses.• Describe the function of the solenid valves.• Read and interpret WHMIS MSDS on compressed gas cylinders.• Demonstrate an ability to assemble the gas cylinder valve and regulators.• Demonstrate an ability to adjust gas fl ow rate to required working rate.

21





Topic: Torches• Make an overhead of fi gure 32.• Demonstrate how to disassemble a torch body.

Topic: Regulators and Flowmeters• Review the set-up and operation of regulators and fl owmeters.• Create visuals from the ILM.


• Assemble a GTAW air-cooled torch body.• Label diagrams of GTAW torches.

Literacy• Free Writing: Use as a pre-reading strategy. Write for 3 min. on experiences you have had working with torches, regulators, and fl owmeters.




Alberta ILM Graphics CDWelding Period 2



GTAW Electrodes, Filler Metals, and

Shielding Gases (~4 hours Classroom Component)

Introduction A welder apprentice must develop a solid working knowledge of the electrodes, fi ller metals, and shielding gases used in all welding processes. This knowledge enables the ap-prentice to ensure that projects and welds conform to acceptable standards, and will help them to troubleshoot problems related to the welding process.

30. Students will be able to select GTAW electrodes, fi ller metals, and gases.

Assessment

Strategies

Resources Alberta Module 120202b, GTAW Electrodes, Filler Metals and Shielding GasesNational Occupational Analysis (NOA), Human Resources and Skills Development Canada (HRSDC): Occupational Analyses Series - WelderStudentsAchieve (http://sas.edu.pe.ca)

Students will be expected to30.1 identify the function of the electrode in GTAW30.2 identify electrodes by AWS designations and explain their applications30.3 explain and demonstrate the care and preparation of electrodes30.4 identify the function of the fi ller metals in GTAW30.5 identify fi ller metals by AWS and CSA designations and explain their applications30.6 identify types and purpose of consumable inserts30.7 explain the care and handling of fi ller metals30.8 describe the types and applications of shielding gases used in GTAW30.9 describe the advantages and disadvantages of various types of shielding gases

Specifi c

Curriculum

Outcome

SCO - Delineations


24



GTAW Electrodes, Filler Metals, and Shielding Gases (~4 hours Classroom Component)SCO 30. Students will be able to select GTAW electrodes, fi ller metals, and gases.



30.1 identify the function of the electrode in GTAW

30.2 identify electrodes by AWS designations and explain their applications

30.3 explain and demonstrate the care and preparation of electrodes

Topic: GTAW Electrodes• Describe the function of the electrode used for GTAW.• State the characteristics of tungsten that make it an effective electrode.• State the four alloying elements used to create tungsten alloys.

• Interpret AWS specifi cations for identifying GTAW electrodes.• State factors to consider when selecting a tungsten electrode.• Describe the function and intended use of common GTAW electrodes.• Identify the fi nish on the electrode.• Interpret data related to electrode selection from manufacturers’ tables and specifi cations.

Topic: Care and Preparation• Describe the purpose of preparing electrodes.• State the application of tapered ends.• State the application of balled ends.• Describe the three methods of preparing electrodes.• Explain why grinding marks should be longitudinal.• Discuss how to keep an electrode in good condition when welding.• Practise safe work habits when handling and preparing electrodes.• Describe factors that infl uence electrode end conditions.• Predict potential problems based on the condition of the electrode.

25






Topic: GTAW Electrodes• Have a variety of common GTAW electrodes for display and for circulation through the class.• Review the AWS standards for the classifi cation of GTAW electrodes.

Topic: Care and Preparation• Create a slideshow using images from the graphics CD to help illustrate the various types of electrode preparation.• Demonstrate how to properly prepare an electrode.• Demonstrate how to inspect and recondition an electrode.

• Prepare GTAW electrodes for shop projects.• Recondition GTAW electrodes.• Select the appropriate GTAW electrode for shop projects.

Literacy• Free Writing: Use as a pre-reading strategy. Write for 3 min. on experiences you have had identifying and working with welding electrodes.

Texts / Teacher ResourcesAlberta Module 120102bGTAW Electrodes, Filler Metals, and Shielding Gasespp. 2-13



Alberta ILM Graphics CDWelding Period 2

26






30.4 identify the function of the fi ller metals in GTAW

Topic: Filler Metals • Identify various forms of fi ller metals.• Describe factors to consider when selecting a fi ller metal.

• Describe AWS and CSA designations.• Interpret specifi cation tables related to fi ller metals for GTAW.• Explain the characteristics of commonly used fi ller metals.

• Describe advantages of using consumable inserts.• Identify various forms of consumable inserts and state their intended function.

• Practise proper care and handling of fi ller metals.

30.5 identify fi ller metals by AWS and CSA designations and explain their applications

30.6 identify types and purpose of consumable inserts

30.7 explain the care and handling of fi ller metals

27





Topic: Filler Metals and Consumable Inserts• Have a variety of common GTAW fi ller metals for display and for circulation through the class.• Review the AWS standards for the classifi cation of GTAW fi ller metals.• Demonstrate the application of a consumable insert and joint preparation.• Discuss the care and handling of GTAW fi ller metals.


• Component ID: Identity a variety of fi ller metals and electrodes used with GTAW.• Prepare joints for consumable inserts.• Demonstrate proper care and handling of GTAW fi ller metals and electrodes.




28






30.8 describe the types and applications of shielding gases used in GTAW

30.9 describe the advantages and disadvantages of various types of shielding gases

Topic: Shielding Gases• Defi ne terms related to shielding gases.• Interpret WHMIS information.• Explain the function of the shielding gas.• State the general application of each of the following shielding gases used for GTAW: - argon - helium - nitrogen - argon helium - argon hydrogen• Demonstrate an ability to regulate shielding gas fl ow rates.

Topic: Advantages and Disadvantages• Demonstrate an understanding of the advantages of various shielding gases.• Demonstrate an understanding of the disadvantages of various shielding gases.

29





Topic: Shielding Gases• Review the terms related to shielding gases.• Review the function and characteristics of shielding gases, and relate the content back to experiences the students would have had working with shielding gases in GMAW welding.

Topic: Advantages and Disadvantages• Discuss table 4 and table 5 in the ILM (pp. 27-28).


• Identify shielding gas problems from sample welds.• Copy and complete a chart similar to the example below.

Gas Characteristics / Applications Cost Metals

LiteracySummarizing: Use as a post-reading strategy. Use a graphic organizer similar to the example shown to help illustrate the advantages and disadvantages of GTAW.






GTAW Equipment Maintenance and

Troubleshooting (~3 hours Classroom Component)

Introduction Keeping welding equipment running smoothly not only results in better quality welds, but also improves effi ciency, which helps reduce the high cost of equipment down time. The more knowledgeable apprentices are about the function, operation, and maintenance of GTAW equipment, the better prepared they are to set welding parameters, diagnose problems, and take preventative steps to avoid future problems.

31. Students will be able to maintain and troubleshoot GTAW equipment.

Assessment

Strategies

Resources Alberta Module 120102c, GTAW Equipment Maintenance & TroubleshootingNational Occupational Analysis (NOA), Human Resources and Skills Development Canada (HRSDC): Occupational Analyses Series - WelderStudentsAchieve (http://sas.edu.pe.ca)

Students will be expected to31.1 diagnose power source output current problems and demonstrate corrective measures31.2 diagnose GTAW torch and cable assembly problems and demonstrate corrective measures31.3 explain the care and handling of GTAW equipment and components31.4 diagnose shielding gas coverage problems and demonstrate corrective measures

Specifi c

Curriculum

Outcome

SCO - Delineations


32



GTAW Equipment Maintenance and Troubleshooting (~3 hours Classroom Component)SCO 31. Students will be able to maintain and troubleshoot GTAW equipment.



31.1 diagnose power source output current problems and demonstate corrective measures

31.2 diagnose GTAW torch and cable assembly problems and demonstrate corrective measures

Topic: Power Sources• Describe factors to consider when setting up and maintaining GTAW power sources: - location and hookup of the welding power source - torch assembly - shielding gas and gas control system - work lead - high-frequency current system - shut-down procedures• Interpret manufacturers’ information related to GTAW equipment maintenance.

Topic: Torch and Cable Assemblies• Describe factors to consider when setting up and maintaining GTAW torch and cable assemblies: - torch handle and head - air-cooled GTAW torches - gas control valves - cable covers - nozzles - collet and collet body - gas lens - electrode condition• Interpret manufacturers’ information related to GTAW torches and cable assemblies.

33





Topic: Power Sources• Demonstrate the proper assembly and adjustment of a GTAW set-up.

Topic: Torch and Cable Assemblies• Demonstrate proper care, handling, and inspection of GTAW torch and cable assemblies.

CBL• Guest Speaker: Invite a service person and salesperson from a local machine supplier to speak to the class about equipment maintenance.


• Identify the components of the GTAW set-up.• Correctly set up and adjust a GTAW set-up.• Develop a routine maintenance schedule.

Literacy• Free Writing: Use as a pre-reading strategy. Write for 3 min. on the value of and experiences you have had with equipment maintenance and troubleshooting.

Texts / Teacher ResourcesAlberta Module 120102cGTAW Equipment Maintenance and Troubleshootingpp. 2-18



34






31.3 explain the care and handling of GTAW equipment and components

31.4 diagnose shielding gas coverage problems and demonstrate corrective measures

Topic: Care and Handling• Demonstrate an understanding of the proper care and handling of the following components of the GTAW outfi t: - regulator/fl owmeter unit - hoses - remote control switches - cooling systems

Topic: Shielding Gases• Describe the following common problems related to shielding gases: - inadequate gas fl ow - excessive gas fl ow - incorrect gas selection• Describe the three categories of weld faults. - process - electrical - mechanical• Demonstrate an ability to diagnose GTAW weld faults related to the categories above.

35





Topic: Care and Handling• Review the proper handling procedures and safety regulations related to a GTAW outfi t.

Topic: Shielding Gases• Review the tables on pp. 24-26 of the ILM.

Literacy• Anticipation Guide: Use as a pre-reading strategy. The questions or statements made should relate to trouble shooting welding equipment with regard to process, electrical and mechanical problems.


• Identify various weld faults related to mechanical, process, and electrical problems.• Implement a routine maintenance schedule.

Texts / Teacher ResourcesAlberta Module 120102cGTAW Equipment Maintenance and Troubleshootingpp. 19-26





GTAW Welds on Mild Steel (~18 of 91 hours Skill Development Component)

Introduction A welder apprentice must be able to perform GTAW welds to an acceptable standard. This module is a hands-on, practical module that will develop students’ ability to perform GTAW welds on mild steel plate.

32. Students will be able to place stringer beads in the fl at position, prepare joints for GTAW, and perform welds in the 1F, 2F, and 3F positions.

Assessment

Strategies

Resources Alberta Module 120102d, GTAW Welds on Mild SteelNational Occupational Analysis (NOA), Human Resources and Skills Development Canada (HRSDC): Occupational Analyses Series - WelderStudentsAchieve (http://sas.edu.pe.ca)

Students will be expected to32.1 strike an arc using the touch start or lift start and high-frequency methods32.2 demonstrate the ability to weld stringer beads in the fl at position on mild steel gauge plate32.3 prepare joints for GTAW on mild steel gauge plate32.4 demonstrate the ability to weld fi llet welds in the 1F position on mild steel gauge plate32.5 demonstrate the ability to weld fi llet welds in the 2F position on mild steel gauge plate32.6 demonstrate the ability to weld fi llet welds in the 3F position on mild steel gauge plate

Specifi c

Curriculum

Outcome

SCO - Delineations


38



GTAW Welds on Mild Steel (~18 of 91 hours Skill Development Component) SCO 32. Students will be able to place stringer beads in the fl at position, prepare joints for GTAW, and perform welds in the 1F, 2F, and 3F positions.



32.1 strike an arc using the touch start or lift start and high frequency methods

Topic: Starting the Arc• Demonstrate an understanding of the factors to consider when assessing the value of any welding technique.• Describe and practise safety procedures related to GTAW processes.• Defi ne the terms identifi ed on pp. 3-4 of ILM 120202d.• Interpret welding procedure specifi cations.• Create welding procedure specifi cations.• Perform welding techniques used for GTAW.• Demonstrate the ability to start the arc by means of - scratch start - high frequency start - lift start.

39






Topic: Starting the Arc• Create a slideshow to illustrate the proper method of starting the arc.• Demonstrate proper starting techniques.

• Create a Welding Procedure Specifi cation (WPS) for eacj shop project.• Have the students fold a piece of blank paper in half. Label the top half “scratch start” the bottom half “high-frequency start,” and the back “lift start”. Have students practice both methods of striking an arc by using a pencil or a felt tip marker. The marks left on the paper will help determine students’ understanding of both methods. Observe each student for proper technique and arc length.

Literacy• Summarizing: Use as a post-reading strategy after you have read the exercise.

Texts / Teacher ResourcesAlberta Module 120102dGTAW Welds on Mild Steelpp. 2-10



40






32.2 demonstrate the ability to weld stringer beads in the fl at position on mild steel gauge plate

32.3 prepare joints for GTAW on mild steel gauge plate

32.4 demonstrate the ability to weld fi llet welds in the 1F position on mild steel gauge plate



• For each of the exercises in the ILM that relate to outcomes 32.2–32.6 demonstrate the ability to - select/prepare and identify correct materials - prepare work area - interpret welding parameters - evaluate the quality of the fi nal weld.

41





• Review and demonstrate proper safety procedures.• Demonstrate set-up of GTAW welding parameters.• Perform a class demonstration for each of the exercises.


Complete each of the exercises in the ILM.

Literacy• Summarizing: Use as a post-reading strategy after you have read the exercise.

Enrichment / Research Activities

• Participate in Skills Canada competitions.

Texts / Teacher ResourcesAlberta Module 120102dGTAW Welds on Mild Steelpp. 11-29



welding technology - government of prince edward · pdf filegas tungsten arc welding is a...

Documents