Chapter 21 GMAW- Applications All Possible Questions and Answers with complete solution

1. Steel from 1/4" to 1/2" thick may be butt welded with no edge preparation. Answer: False 2. The backhand technique is generally used for welding stainless steel. Answer: False 3. Using short circuiting transfer on aluminum produces a colder arc than is produced with spray transfer. Answer: True 4. When using GMAW on aluminum, a lower current than that used for other metals is required. Answer: True 5. A 95% Ar/5% O2 shielding gas mixture provides higher heat input when welding aluminum between 1" and 2" thick. Answer: False 6. When welding stainless steel more than 1/4" thick using GMAW, a slight side-to-side movement should be used. Answer: True 7. Spray transfer is commonly used for thin stainless steel in overhead position. Answer: False 8. Using GMAW on copper is usually restricted to the deoxidized types of copper. Answer: True 9. The preferred shielding gas for welding thin copper is argon. Answer: True 10. An argon back-up gas may be used when welding stainless steel to prevent air from contacting the underside of the weld, causing embrittlement. Answer: True 11. For short circuiting transfer on carbon steels and low-alloy steels, the preferred shielding gas is _______. Answer: A mixture of 75% argon and 25% CO212. A 50° to _____° groove angle is required on carbon steel up to 1" thick. Answer: 60 13. For carbon steel welded without edge preparation, a _____" root opening is recommended. Answer: 1/16