welding: intro to the gmaw machine gas metal arc welding (“mig”) copyright © texas education...

Welding:Intro to the GMAW Machine

Gas Metal Arc Welding (“MIG”)

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Illustration

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Chart

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Machine

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Gun

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Wire Feeder

Copyright © Texas Education Agency, 2012. All rights reserved.

Wire feeder

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Advantages

• High quality welds can be produced much faster

• Since a flux is not used, there is no chance for the entrapment of slag in the weld metal resulting in high quality welds

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Advantages

• The gas shield protects the arc so that there is very little loss of alloying elements. Only minor weld spatter is produced.

• Very versatile and can be used with a variety of metals and alloys

• Can be operated several ways, including semi and fully automatic

Copyright © Texas Education Agency, 2012. All rights reserved.

Copyright © Texas Education Agency, 2012. All rights reserved.

MIG Disadvantages• Generally not used in overhead welding

position because of the high heat input and the fluidity of the weld puddle

• Complex equipment

• Wire can “squirrel’s nest”