Weld 140 GMAW Chapter Reviews Name: _______________________________________ Date: _____________ SUMMER SCHEDULE Required Reading: Welding Principals and Applications 7th Edition Larry Jeffus Due Week 1: Review Test Chapter 10 – Gas Metal Arc Welding Equipment, Setup and Operation (23 points). Review Test Chapter 11 – Gas Metal Arc Welding (27 points). Weld 140 GMAW Chapter Reviews Page 1 of 9 (Revised 7-1-2014) THIS PAGE LEFT INTENTIONALLY BLANK Weld 140 GMAW Chapter Reviews Page 2 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 10 Name: _______________________________________ Date: _____________ Required Reading: (Welding Principals and Applications 7th Edition Larry Jeffus Chapter 10) Review Test Chapter 10 answer all questions 1 through 23 Total Points (23) 1. Why is usage of the term GMAW preferable to MIG for gas metal arc welding? _____________________________________________________________________________________ 2. Using Table 10-1, answer the following: a. What maintains the arc in machine welding? ____________________ b. What feeds the filler metal in manual welding? ____________________ c. What provides the joint travel in automatic welding? ____________________ d. What provides the joint guidance in semiautomatic welding? ____________________ 3. In what form is metal transferred across the arc in the axial spray metal transfer method of GMA welding? _____________________________________________________________________________________ _____________________________________________________________________________________ 4. What three conditions are required for the spray transfer process to occur? _____________________________________________________________________________________ _____________________________________________________________________________________ 5. Using Table 10-3, answer the following: a. What should the wire-feed speed and voltage ranges be to weld 1/8-in. (3 mm) metal with 0.035-in. (0.90mm) wire using argon shielding gas? ____________________ b. What should the amperage and voltage range be using 98% Ar + 2% O2 to weld 1/4-in. metal with 0.045-in. wire? ____________________ 6. What ranges does the pulsed-arc metal transfer shift between? _____________________________________________________________________________________ _____________________________________________________________________________________ 7. Why is helium added to argon when making some spray or pulsed-spray transfer welds? _____________________________________________________________________________________ _____________________________________________________________________________________ 8. Why does DCEP help with welds on metals such as aluminum? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 3 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 10 Name: _______________________________________ Date: _____________ 9. Why is CO2 added to argon when making GMA spray transfer welds? _____________________________________________________________________________________ 10. *Using Figure 10-12 (page 245), what is the approximate voltage at 150 amps at 200 in./min? _____________________________________________________________________________________ 11. Using Table 10-6, what would the amperage be for 0.035-in. (0.9-mm) wire at 200 in./min (5 m/min)? _____________________________________________________________________________________ 12. What may happen if the GMA welding electrode is allowed to strike the base metal outside of the molten weld pool? _____________________________________________________________________________________ 13. What effect does shortening the electrode extension have on weld penetration? _____________________________________________________________________________________ 14. Describe the weld produced by a backhand welding angle. _____________________________________________________________________________________ 15. Describe the weld produced by a forehand welding angle. _____________________________________________________________________________________ 16. What components make up a GMA welding system? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 17. Why must GMA welders have a 100% duty cycle? _____________________________________________________________________________________ 18. What can happen if rollers of the wrong shape are used on aluminum wire? _____________________________________________________________________________________ _____________________________________________________________________________________ 19. Where is the drive motor located in a pull-type wire-feed system? _____________________________________________________________________________________ 20. How is the wire-feed speed changed with a linear feed system? _____________________________________________________________________________________ _____________________________________________________________________________________ 21. What type of liner should be used for aluminum wire? _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 4 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 10 Name: _______________________________________ Date: _____________ 22. What parts of a typical GMA welding gun can be replaced? _____________________________________________________________________________________ 23. Describe the spot welding process using a GMA welder. _____________________________________________________________________________________ _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 5 of 9 (Revised 7-1-2014) THIS PAGE LEFT INTENTIONALLY BLANK Weld 140 GMAW Chapter Reviews Page 6 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 11 Name: _______________________________________ Date: _____________ Required Reading: (Welding Principals and Applications 7th Edition Larry Jeffus Chapter 11) Review Test Chapter 11 answer all questions 1 through 27 Total Points (27) 1. What items make up a basic semiautomatic welding system? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 2. What must be done to the shielding gas cylinder before the valve protection cap is removed? _____________________________________________________________________________________ 3. Why is the shielding gas valve “cracked” before the flowmeter regulator is attached? _____________________________________________________________________________________ 4. What causes the electrode to bird nest? _____________________________________________________________________________________ 5. Why must all fittings and connections be tight? _____________________________________________________________________________________ 6. What parts should be activated by depressing the gun switch? _____________________________________________________________________________________ 7. What benefit does a welding wire’s cast provide? _____________________________________________________________________________________ 8. What can be done to determine the location of a problem that stops the wire from being successfully fed through the conduit? _____________________________________________________________________________________ _____________________________________________________________________________________ 9. What are the advantages of using a feed roller pressure that is as light as possible? _____________________________________________________________________________________ _____________________________________________________________________________________ 10. Why should the feed roller drag prevent the spool from coasting to a stop when the feed stops? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 7 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 11 Name: _______________________________________ Date: _____________ 11. Why must you always wind the wire tightly into a ball or cut it into short lengths before discarding it in the proper waste container? _____________________________________________________________________________________ _____________________________________________________________________________________ 12. What reactive gases are used with argon for GMA welding on steels? _____________________________________________________________________________________ 13. What effect on the welding current does increasing the wire feed speed have? _____________________________________________________________________________________ 14. Why would the flowmeter ball float at different heights with different shielding gases if the shielding gases are flowing at the same rate? _____________________________________________________________________________________ 15. Using Table 11-1, determine the amperage if 400 in. (10.2 m/min) of 0.45-in. (1.2-mm) steel wire is fed in one minute. _____________________________________________________________________________________ 16. How is the amperage adjusted on a GMA welder? _____________________________________________________________________________________ 17. What happens to the weld as the electrode extension is lengthened? _____________________________________________________________________________________ 18. What is the effect on the weld of changing the welding angle from a dragging to a pushing angle? _____________________________________________________________________________________ 19. What are the advantages of adding oxygen or CO2 to argon for welds on steel? _____________________________________________________________________________________ _____________________________________________________________________________________ 20. What are the advantages of using CO2 for making GMA welds on steel? _____________________________________________________________________________________ _____________________________________________________________________________________ 21. What is mill scale? _____________________________________________________________________________________ 22. What type of porosity is most often caused by mill scale? _____________________________________________________________________________________ 23. What should the welder watch if the view of the weld is obstructed by the shielding gas nozzle? _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 8 of 9 (Revised 7-1-2014) Weld 140 GMAW Review Test Chapt. 11 Name: _______________________________________ Date: _____________ 24. When making a vertical weld and it appears that the weld metal is going to drip over the shelf, what should you do? _____________________________________________________________________________________ _____________________________________________________________________________________ 25. What are the advantages of making vertical down welds? _____________________________________________________________________________________ 26. How can small weld beads be maintained during overhead welds? _____________________________________________________________________________________ 27. How can spatter be controlled on the nozzle when making overhead welds? _____________________________________________________________________________________ _____________________________________________________________________________________ Weld 140 GMAW Chapter Reviews Page 9 of 9 (Revised 7-1-2014)
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