Lab sheet JJ103
- 1. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING NO OF PROJECT : K/03/PJB TITLE : ARC WELDING – Parallel Long Beads 1.0 COURSE LEARNING OUTCOMES Upon completion of this workshop, students should be able to : 1.1 practice correctly safety procedures in the workshop ; and 1.2 carry out correctly basic gas welding works involving various processes of welding and types of joining metals according to SOP. 2.0 OBJECTIVES 2.1 Welding long beads in parallel (Refer to diagram K/03/PJB) 3.0 APPARATUS/EQUIPMENT 3.1 Arc welding equipment 3.2 Face shield 3.3 Chipping hammer 3.4 Plier 3.5 Wire brush 3.6 Electrode E6013 (φ2.6mm or 3.25mm) 3.7 Leather hand glove 4.0 MATERIAL 4.1 Mild steel flat bar (100mm x 50mm x 2mm) LIANA FAIRUZ BINTI ZAKARIA 1
- 2. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING List out the apparatus/equipment and material Draw the apparatus/equipment and material used in the workshop LIANA FAIRUZ BINTI ZAKARIA 2
- 3. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING 5.0 SAFETY AND HEALTH It is the individual’s responsibility to practice the following general safety guidelines at all times and keep your workspace reasonably tidy. 5.1 Always know the hazards associated with the equipment/materials that are being utilized in the workshop. 5.2 Always wear appropriate protective clothing and equipment. 5.3 Confine long hair and loose clothing. Do not wear high-heeled shoes, open-toed shoes, sandals or shoes made of woven material. 5.4 Be familiar with the location of emergency equipment such as fire alarm and fire extinguisher. Know the appropriate emergency response procedures. 5.5 __________________________________________________________________________ __________________________________________________________________________ 5.6 __________________________________________________________________________ __________________________________________________________________________ 5.7 __________________________________________________________________________ __________________________________________________________________________ 5.8 __________________________________________________________________________ __________________________________________________________________________ 5.9 __________________________________________________________________________ __________________________________________________________________________ 6.0 INTRODUCTION 6.1 Theory Arc welding is a type of a welding that produces coalescence in metals by heating them with an electric arc. The arc is struck between a welding electrode and the base metal. The welding electrode is a component of the welding circuit that terminates at the arc. The joint area is shielded from the atmosphere until it is cool enough to prevent the absorption of harmful impurities from the atmosphere. Figure 1 : Arc Welding Working Principle LIANA FAIRUZ BINTI ZAKARIA 3
- 4. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING Arc welding process produces an arc between a consumable, coated electrode and the work piece, creating a weld pool. The arc and molten weld pool are protected by shielding gas produced by the electrode coating. The electrode coating also contains flux that forms a protective slag over the weld. Figure 2 : Arc welding is a versatile process that does not require external shielding gas Before proceeding with any welding operation, welders must understand common welding terms. The base metal is the metal or alloy that is to be welded. An electrode is a component of welding circuit that conducts electrical current to the weld area. Electrodes may be consumable or non-consumable, depending on the welding process. Consumable electrodes are depleted during welding, non-consumable electrodes are not. A weld bead is a weld that results from a weld pass. A weld pass is a single progression of welding along a weld joint. 7.0 PROCEDURES 7.1 Cut the mild steel flat bar to the specified size. 7.2 Clean the surface and sharp edge of the work piece. 7.3 Prepare the arc welding equipment and make sure all the cable is tightly installed. 7.4 Switch on the welding machine and set the alternate current within 90A to 120A. 7.5 Put the work piece on the work bench on the flat position. 7.6 Strike the arc either using tapping method or scratching method. 7.7 Weld from left to right. Move the electrode using drag travel technique. 7.8 Set the electrode angle at 70° to 80° to the weld movement and 90° to the work piece side. 7.9 Weld with uniform angle and travel speed during the weld pass. 7.10 Keep the arc length between 2mm to 3mm and is uniform throughout the weld pass. 7.11 Repeat the process(7.7 to 7.10) for next weld pass until all part completely welded. 7.12 After completion, strike weld area with chipping hammer and remove remaining slag with wire brush. LIANA FAIRUZ BINTI ZAKARIA 4
- 5. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING PROCEDURES DIAGRAM (with label) LIANA FAIRUZ BINTI ZAKARIA 5
- 6. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING PROCEDURES DIAGRAM (with label) LIANA FAIRUZ BINTI ZAKARIA 6
- 7. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING 8.0 RESULT Draw the work piece with the dimension. 9.0 DISCUSSION 9.1 Why should leather gloves be worn when welding? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 9.2 Why should a welder never look at an electric arc without eye protection? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 9.3 How should slag from a weld be removed from a work piece? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 9.4 How does arc length affect a weld? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ LIANA FAIRUZ BINTI ZAKARIA 7
- 8. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING 10.0CONCLUSION __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 11.0 REFERENCES 11.1 B.J Moniz and R.T. Miller (2010).Welding Skills Fourth Edition. American Technical Publishers. Orland Park, Illinois. 11.2 ________________________________________________________________________ ________________________________________________________________________ 11.3 ________________________________________________________________________ ________________________________________________________________________ LIANA FAIRUZ BINTI ZAKARIA 8
- 9. JJ103 MECHANICAL ENGINEERING PRACTICE 1 ARC WELDING PROJECT MARKING SCHEME MARK(S) GIVEN MARKING MARK(S) MAXIMUM ASSESSMENT CRITERIA FACTOR OBTAINED MARKS 4 3 2 1 0 Uniform width and height of weld beads 4 16 Fine and even weld beads 4 16 Convex shape of weld beads 4 16 Weld beads size according to the standard 4 16 No overlapping and undercut beads 4 16 Even starting and finishing 4 16 Clean and neat work piece 1 4 TOTAL MARKS 100 REPORT MARKING SCHEME MARK(S) MAXIMUM ASSESSMENT CRITERIA COMMENT OBTAINED MARKS Front cover 5 Apparatus/equipment and material 15 - list out and draw the diagram correctly Safety and health 15 Procedures 25 - write the procedures in order and use passive sentences Result 5 - draw the work piece with dimension Discussion - Question 9.1 5 - Question 9.2 5 - Question 9.3 5 - Question 9.4 5 Conclusion 5 References 5 Report neatness 5 TOTAL MARKS 100 Lecturer’s Signature, ___________________ Date : LIANA FAIRUZ BINTI ZAKARIA 9