shielded metal arc welding · this programme, shielded metal arc-welding, or smaw, has been...

SHIELDED METAL ARC WELDING

(SMAW)

Facilitator Guide

TABLE OF CONTENTS INTRODUCTION PAGE 1 THE LEARNING PROCEDURE PAGE 2 OUTCOMES / ASSESSMENT CRITERIA PAGE 4 MODEL ANSWERS TO SELF-TEST (THEORY) PAGE 6 PRACTICAL EXERCISES CRITERIA PAGE 15

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INTRODUCTION This programme, Shielded Metal Arc-Welding, or SMAW, has been designed to introduce Learners to the fundamental skills involved in the use of conventional metal arc-welding processes. The emphasis of this series is geared toward "safety" and "practical techniques" in basic (core) skills. No attempt has been made to include "advanced techniques" in this programme. Learners are guided through the learning process via a Learning-Guide and it is in this sense that the programme is "Learner Driven". A competent "Facilitator / Mentor", skilled in the techniques of using SMAW equipment, is an essential factor in the "learning process". IMPORTANT Please be aware that TECH AV programmes are designed as "Training Aids", not "courses". The producers (Natal DVD Productions (Pty) Ltd) do not hold themselves responsible for accreditation of this or any other material produced under the Tech AV trade name. Any tests, exercises and assessments provided in the "Learning Guides" are offered as "suggestions" and do not necessarily conform to the criteria set by the authoritative SETA. PRE-REQUISITES (Learning Assumed to be in place) It is assumed that those participating in this programme have successfully achieved competency / proficiency in the following:

o General Industrial safety. o Use of Basic Engineering Hand-Tools. o Basic measuring skills.


THE LEARNING PROCEDURE LEARNERS GUIDE (WORKBOOK)

o Each Learner should be supplied with a copy of the Learners' Guide. This should be retained in the possession of the Learner for future reference.

o The Learners' Guide serves to direct the Learner through the programme. EXERCISES AND SELF-TESTS

o Exercises and Self-Tests normally accompany each section of learning. The Learner performs these after having read the relevant "resource notes" and viewed the relevant section of video (where applicable).

o "Model Answers" to the theoretical tests are provided in this manual. o Practical exercises are assessed upon the "output criteria" and upon "safe working

practices". VIDEO PROGRAMMES

o A Learner will request the relevant video for the section he or she is attempting. o Learners must be permitted to view a video as many times as deemed necessary in

order to grasp a concept or observe a demonstration. o Each video is divided into sections. Learners should stop the video at the end of each

section and perform any exercise suggested before continuing. LEARNING ENVIRONMENT The primary requisites for a suitable learning environment are:

o A work area where practical exercises can be conducted. LEARNING AIDS

o AC or AC / DC welding machines to maximum 250 amp current output. o All PPE designed for use with arc-welding processes. o Mild steel work-pieces for practice. o Assorted consumables (electrodes). o Manufacturers wall charts or instructional material as available.

RECOMMENDED PROCEDURE FOR LEARNING

o Learner is provided with a copy of the Learning Guide. o Learner reads through the guide to familiarise him/herself with content and

instructions. o Learner views the relevant video section (where applicable) as directed by the

instructions in the guide.


o Learner attempts the suggested exercise, or practices a skill in the workplace. o Learner performs a "self-evaluation" of the work.

EVALUATION Assessment of competencies must be made in accordance with the relevant unit standards applicable to your industrial sector. In broad based terms the following training objectives should be achieved by the Learner:

o Identify by name all equipment associated with SMAW processes. o Prepare work area in terms of safety. o Set up work-pieces and equipment in preparation for welding. o Produce acceptable welding runs.

PROGRAMME STRUCTURE This programme has been divided into (3) main sections. It is recommended that Learners work through these sections in "numerical order". The first section is considered to be "essential" for all processes involving the use of SMAW Equipment.


OUTCOMES / ASSESSMENT CRITERIA PROGRAMME - 1 "SMAW PROCESS AND EQUIPMENT" - (VIDEO 1) OBSERVE (Leaner will perform the following)

o Describe the principles of arc welding. o Describe the SMAW process. o Identify by name all the major components in a typical system. o Describe the 3 basic types of welding machines. o Read and interpret basic "nameplate information". o Identify and describe types of welding leads. o Identify covered electrodes. o Identify basic welders' tools.

CONFIRM

o Learner completes self-tests #1 and #2 (or company test) with 100% result. PROGRAMME - 2 SAFETY AND PPE (VIDEO 2) OBSERVE (Learner performs the following)

o Identify and name the hazards associated with SMAW. o Identify and describe the purpose of standard PPE for SMAW.

CONFIRM

o Learner successfully completes Self-Test #3 and #4. PROGRAMME - 3 "WELDING PROCESSES / TECHNIQUES -PART 1" (VIDEO 3) OBSERVE (Learner will demonstrate the following processes)

o Inspect equipment and prepare work-area. o Set up a typical arc welding machine in preparation for SMAW processes. o Strike arcs and produce "welding-buttons". o Make flat / down-hand stringer-beads on steel plate. o Read a welding bead.

CONFIRM

o Learner successfully completes Self-test #5 and #6. o Work/tasks performed as per Practical Exercise Checklists 1-3.

PROGRAMME - 3 "WELDING PROCESSES / TECHNIQUES -PART 2" (VIDEO 4) OBSERVE (Learner will demonstrate the following processes)

o Weld square-butt joint.


o Weld bevel / single V butt joint. o Weld a "T-Joint".

CONFIRM

o Work / tasks performed as per Practical Exercise Checklists 4 - 6.


MODEL ANSWERS SELF-TEST NO. 1

THE SMAW PROCESS

QUESTIONS YES NO

1. What do the letters “SMAW” stand for? Shielded Metal Arc Welding.

2. List the main components of a SMAW set-up i) Welding Machine. ii) Welding leads. iii) Electrode Holder. iv) Electrode.

3. What 3 names are sometimes used for the welding-lead that connects the machine to the work-piece? i) Work-lead. ii) Ground-lead. iii) Earth-lead.

4. What is the other welding-lead called? The Electrode Lead.

5. What are the two basic tools required by a welder? i) Chipper hammer. ii) Wire brush.

6. Give 2 purposes for the “flux coating” on a covered electrode. i) Creates a layer of “shielding gas”. ii) Creates a layer of slag over the weld.

7. Why is slag important? It protects the weld from the atmosphere during the cooling period.


SELF-TEST NO. 2 BASIC EQUIPMENT

QUESTIONS YES NO

1. What are the 3 basic types of welding machines? i) AC machines. ii) DC machines. iii) AC / DC machines or Combination machines.

2. What "current range" is required for most SMAW operations? 50 – 600 Amps.

3. In DC terms, what is "straight polarity"? When electrode is connected to the “negative” output.

4. What does the term "DCEN" mean? Direct current, electrode negative.

5. What must you be sure to do before you change polarity on a machine? Switch the machine off.

6. What are the main details, from the welder’s point of view, that you can read from a "name-plate"? i) Input power requirements. ii) Output current type and value. iii) Operating voltages – OCV. iv) Duty Cycle.

7. If a machine has a duty cycle of 20% at its maximum output, how long can it be operated before it has to cool? 2 Minutes.

8. What factors in a "welding-lead / cable" determines the maximum current that it can carry? i) Core diameter. ii) Cable Length.


9. What should you always be wearing when you handle the "live" electrode holder? Welding Gloves.

10. What does the size of an electrode refer to? The diameter of the wire.

11. How should electrodes be stored? In a sealed container or in a “warm box”.

12. List 4 tools that a welder should have available at the work station. i) Chipping Hammer. ii) Wire Brush. iii) Tongs or Heavy pliers. iv) Hammer.


SELF-TEST NO. 3 HAZARDS

QUESTIONS YES NO

1. What are the 4 main hazards associated with SMAW? i) Electric Shock. ii) Eye-Flash or Retinal Burn. iii) Flash Burns. iv) Toxic Fumes.

2. When you have finished using a welding-machine you must do what? Switch it off.

3. Where should the electrode holder be placed when you need both hands to doother things? OFF the workbench or the work.

4. The most likely cause of an electric shock, during a welding operation, would be what? Dampness or wetness.

5. What 3 safety items are intended to prevent your and your work mates', eyes from "eye-flash"? i) Welding Helmet. ii) Flash goggles. iii) Flash screens.

6. What can YOU do to prevent "Flash Burns"? Make sure that no part of your body / skin is exposed to the arc-rays.

7. What is the most important factor regarding "respiratory safety" when you are welding? Adequate ventilation.


8. Name 4 metals/substances that will generate toxic fumes when you weld on materials that contain them. i) Zinc or galvanised steel. ii) Lead. iii) Copper. iv) Cadmium.

9. Before you use an electrode it is wise to do what? Read the warnings, offered by the manufacturer, on the packaging.

10. What safety equipment should always be close by the welding area in the event of fire? Fire extinguisher.

11. When using an "engine-powered" welding machine you must place the machine where? Out-doors or in a well ventilated area.

12. Why is it considered dangerous to weld on or near "used containers"? Because explosive or toxic fumes can be generated.

13. If you receive a BURN whilst welding or handling hot metal, what must you do? Seek immediate medical attention / First aid.


SELF-TEST NO. 4 PPE

QUESTIONS YES NO

1. Name 5 items of PPE that are considered essential for most arc-welding operations: i) Welding helmet / mask. ii) Welding gloves. iii) Leather apron. iv) Skull cap. v) Leather Spats.

2. What items of PPE offer protection against the following? a) Arc rays to the eyes – Mask or Filter lens. b) Skin burns – Mask, gloves, apron and spats. c) Head and hair burn – Skull cap.

3. Complete the statement: "Limited protection from electric SHOCK is provided through leather welding GLOVES providing that they are not WET".

4. When you are chipping hot slag you should be wearing your, what? Welding helmet / mask.

5. In order that you can see what you are doing whilst chipping you should raise the, what? The visor.

6. Apart from the PPE made specifically for "welding tasks" you should also be wearing what when you are welding? i) Overalls. ii) Safety shoes / boots.

THIS CONCLUDES PROGRAMME 2 HAVE YOUR MENTOR / FACILITATOR CHECK YOUR WORK AND THEN MOVE ON TO PROGRAMME

3.


SELF-TEST NO. 5 PREPARATION OF EQUIPMENT AND WORK AREA.

QUESTION (tick correct answer/s) YES NO

1. Before you connect a welding machine to the mains (input) you must do what? (Tick appropriate response) a) Ensure that the power matches the input requirement of

the machine. b) Test the power point for power. c) Call an electrician.

2. If you notice any faults on the welding machine you should do what? (Tick appropriate response). a) Repair all the faults. b) Report all the faults. c) Have a qualified person attend to the faults.

3. Welding leads (cables) must be checked for what? (Tick appropriate responses). a) Insulation damage. b) Makeshift connections. c) Security of connections at the machine. d) Good electrical connection to "ground". e) Colour of the insulation.

4. What checks should be made to an electrode holder? a) The handle and the nose insulation must be in a good

condition. b) The welding lead into the handle must be secure and no

bare wires visible. c) The holder must grip the electrode firmly.

5. It is not recommended that an electrode is "bent", for what reason? As this can crack away the flux coating.

6. When welding in an area where other workers are present you must place what around your work area? Flash Screens.


7. In order to reduce the risk of electrocution you should make sure that you work area is, what? Dry.

8. Welding leads should be positioned in such a way that they, what? (Tick correct responses) a) Do not present a hazard. b) Won't be driven over by vehicles. c) Don't lie upon hot material.


SELF-TEST NO. 6 WELDING MACHINE -STANDARD CONTROLS

AND SET-UP

QUESTIONS YES NO

1. When using a welding machine for the first time what should you do before you start? Read the operators manual or the instructions on the machine.

2. What function does an "isolation switch" perform? It switches the machine off.

3. Why must an oil-cooled machine be kept in an upright position? To prevent oil leaking out.

4. A welding machine should not be connected to the input (mains) until you have done what? Connected the welding leads and the work lead to the work.

5. What should you NOT DO to a machine that has a "forced draft fan"? Switch off the power while it is hot.

6. What 2 things should you NOT DO on a DC machine or a Combination machine whilst that machine is operating? a) Do not change the POLARITY. b) Do not SWITCH between AC and DC.


PRACTICAL EXERCISES CRITERIA CHECK LIST

PRACTICAL EXERCISE NO. 1 - "STRIKING THE ARC" (Welding Buttons) o Check your completed exercise against the criteria in the list below. o Score a "Yes" (tick the block) if the work meets the criteria described. o Score a "No" if the work does not meet the criteria. o Repeat the exercise until you are able to score a YES to all criteria. o Have your Facilitator / Mentor check your work.

CRITERIA YES NO

1. Your metal work-piece has been cleaned up and is rust / scale free?

2. The work-lead ground connection is contacting "bright metal".

3. The current setting is at 120 amps (approximately).

4. You have selected the correct electrode.

5. You are, or were, wearing the necessary PPE? 6. You have managed to produce welding "buttons" over the full

face of the work-piece?

7. You are satisfied that you can strike an arc?

8. Have you asked your Mentor / Facilitator to check your work?


Answer the following questions:

QUESTION YES NO

1. List the possible reasons that could cause the electrode to "stick" to the work-piece when you attempt to strike the arc. i) Amperage set too low. ii) A poor electrical contact between the work and the

table / earth connection. iii) The electrode is damp. iv) Striking-action is too slow.

2. What should you do if the electrode sticks? (Tick the appropriate response) a) Pull the "ground clamp off the welding table". b) Shut down the machine. c) Quickly release the electrode from the holder.

CHECK LIST

FOR PRACTICAL EXERCISE NO.2 -"LAYING OF STRINGER-BEADS" o Check your completed exercise against the criteria in the list below. o Score a "Yes" (tick the block) if the work meets the criteria described. o Score a "No" if the work does not meet the criteria. o Repeat the exercise until you are able to score a YES to all criteria. o Have your Facilitator / Mentor check your work.

CRITERIA YES NO

1. The work-piece is clean and a good "earth connection" is / was established?

2. You were / are wearing the necessary PPE?

3. You successfully made at least 2 full beads along the work-piece?

4. The beads are straight, or on the lines.

NOTE: Other Criteria will be explained in the next procedure.


EXERCISE NO. 3 - CLEAN AND READ A WELD-BEAD INSTRUCTIONS

o Using your previous exercise (stringer beads), clean all the beads by chipping and brushing.

o "Read" the welding beads. o Enter you findings in the table/list below and suggest what "corrective action" you

need to make in order to improve the quality. o Have your Facilitator / Mentor check your work.

BEAD No. On this bead I “read”… …and the action to correct this is?

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.


CHECK LIST FOR PRACTICAL EXERCISE NO. 4 - "SQUARE BUTT JOINT"

o Check your completed exercise against the criteria in the list below. o Score a "Yes" (tick the block) if the work meets the criteria described. o Score a "No" if the work does not meet the criteria. o Repeat the exercise until you are able to score a YES to all criteria. o Have your Facilitator/Mentor check your work.

CRITERIA YES NO

1. The plates are clean and there is/was a good electrical contact to the work?

2. You are / were wearing all necessary PPE?

3. A 3,15 mm root-gap was set between the plates.

4. The "horizontal alignment" is "flat" after "tack-welding".

5. First bead shows correct "penetration".

6. All slag removed from the bead and the root penetration.

7. Reverse side bead has been made and cleaned.

8. Beads are of consistent width @ approximately 6 mm wide.

9. Your Mentor / Facilitator has checked your work.


EXERCISE NO. 5 - SINGLE GROOVE BUTT-JOINT INSTRUCTIONS

o Perform this exercise using 10 mm M/S plate. o Cut plates to size (approximately 150 x 75 mm strips). o Bevel the edges to 30 degrees. o Weld the plates together using 3 passes. o Check your work in 3 stages as outlined below.

Check No. 1 - Preparation and Root Run

CRITERION YES NO 1. Work-pieces have been cleaned and a good electrical connection

exists to the work-lead.

2. You are / were wearing the necessary PPE. 3. Plates have been prepared/bevelled to produce a 60⁰ included

angle.

4. A 3,15 mm root-gap was provided.

5. Work was given a "pre-set" after tack welds made. 6. Root-run made correctly, to produce a thin bead of "protrusion"

along the reverse side.

7. All slag has been removed from the root run.

8. Your Mentor / Facilitator has inspected the work to this stage.

Check No.2 - Hot Pass

CRITERION YES NO

1. Correct electrode size (4 mm) selected.

2. Current setting changed for electrode (160 amps).

3. Bead has been run, cleaned and inspected for quality.

4. Your Mentor / Facilitator has inspected your work to this stage. Check No.3 - Capping Run

CRITERION YES NO 1. Correct electrode size (3.15 mm selected. 2. Current setting adjusted to electrode selection. 3. Bead is welded, using small weaving process. 4. Bead is chipped and cleaned. 5. Bead shows consistent width and meets acceptable quality in appearance.

6. Mentor / Instructor has checked your work.


EXERCISE NO. 6 - "T-JOINT / FILLET WELD" INSTRUCTIONS

o Perform this exercise using 6 mm M/S plate. o Cut plates to size (approximately 150 x 50 mm strips) o Set up the plates to form a "T-Joint", with suitable supports, on your welding bench. o Weld the joint using 3.15 or 4 mm electrodes. o Check your work against the "criteria" given in the check-list for practical exercise

No. 6.


CHECK-LIST

FOR PRACTICAL EXERCISE NO. 6 o Check your completed exercise against the criteria in the listing below. o Score a "YES" response (tick the block) if the work meets the criteria described. o Score a "NO" response if the work does not meet the criteria described. o Repeat the exercise, if necessary, until you are able to score a "YES" response to all

the criteria. o Have your Facilitator / Mentor check your work and sign off this exercise when

completed.

CRITERIA YES NO

1. Work-pieces are clean and edges are straight / square.

2. Welding-current set to correct setting for electrode used.

3. Upright leg is set to 90u after tacking.

4. Weld faces (both) are of uniform width (6 - 8 mm wide).

5. Both welding beads meet "acceptable standard".

6. Your Mentor / instructor has checked your work?

Facilitator / Mentor signature: _______________________ Date: _______________

THIS CONCLUDES THE SHIELDED METAL ARC SERIES.

shielded metal arc welding · this programme, shielded metal arc-welding, or smaw, has been...

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