10.8 Chapter Conclusion

Stephanie Oostman

Summary

Gas Metal Arc Welding can be used with both ferrous and non-ferrous metals. The machine used is a constant voltage aka CV power type machine, and can be outfitted with different components so that it can also use Flux-cored wire aka FCAW. Changing the wire feed speed, gas type, and voltage will change how the welding wire melts and becomes a weld. The balance of these different settings create ‘transfer modes’ of which there are four basic types, spray transfer, spray transfer pulsed, Short circuit and globular. Gas metal arc welding can be used with inter or active gasses which created the slang terms ‘MIG’ or ‘MAG’ welding. The machine is not very portable, limiting its usability to garages and fabrication shops. There are also different GMAW guns such as a spool gun or push-pull gun which allows for better mobility of a welder and cuts down on wire jamming.

A welder should be comfortable and familiar with the internal components of the machine and be able to resolve wire jamming and changing the wire spools.

Review Questions

  1. What are the different transfer modes for GMAW?
  2. What type of gas is most common?
  3. Can a welding machine set up for GMAW also be used for FCAW ?
  4. If #3 is a yes, what equipment do you need to change out? If #3 is no, why not?
  5. What polarity is GMAW aluminum used with?
  6. What is GMAW-P?
  7. Describe pinch force effect.
  8. Explain the concerns when selecting globular transfer.
  9. Are there any recommended oscillation patterns when MIG welding stainless steel joints thicker than ¼’’ ?
  10. Are there different guns you learned about in Chapter 9 that would be appropriate for GMAW aluminum?

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Introduction to Welding Copyright © by Washington State Board for Community and Technical Colleges is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.