MWT 2020 - Basic Gas Metal Arc Welding

• Identify the modes of GMAW transfer, including short-circuiting transfer, axial-spray transfer and globular transfer 

• Describe the advantages of pulse-arc waveforms for controlled heat and penetration applications 

• Identify the common shielding gases and gas mixtures and the reasons for the 

matching 

gas mixtures to the transfer mode being performed 

• Identify and select the proper size and class of GMAW filler wire for a given application 

• Explain how wire-feed rates are measured and the effects of wire-feed rates on weld deposition rates and how Voltage/Wire-feed rates determine welding amperage of CV power sources 

• Describe the term stringer-bead and weave-bead and the defining characteristics of both 

• Demonstrate how to perform a stringer bead on plate steel using short-circuiting transfer 

• Describe the term “dig and fill”, and the variations of dig and fill weld puddle 

• Describe how manipulating the molten weld puddle can effect penetration, heat control and weld bead aesthetics 

• Demonstrate how to perform a “dig and fill” manipulated weld bead on plate steel 

using short circuiting transfer 

• Demonstrate how to perform single pass fillet welds on lap-joints and Tee-joints in the 1F and 2F positions using short-circuiting transfer 

• Demonstrate how to perform multi-pass fillet welds on Tee-joints on the 2F position using short-circuiting transfer 

• Demonstrate how to perform open-root, square groove butt joints in the 1G and 2G positions using short-circuiting transfer 

• Demonstrate how to prepare a beveled surface on plate steel coupons 

• Demonstrate how to properly set-up and tack weld a single Vee, butt-joint coupon with backing 

• Demonstrate how to perform a multi-pass weld on a single Vee, Butt-joint coupon with backing