dropthepuck
Petroleum
Why is a purge or backing gas not necessary when welding carbon steel using the gtaw process but is necessary when welding higher chromes. Is it the chrome content?en
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GTAW
- Thread starter dropthepuck
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Well yes, plus the different effects of oxidising carbon steel and stainless steel. The stainless steel is more dependent upon maintaining a 'pristine' surface for such things as corrosion performance than is carbon steel. A heavily scaled stainless steel won't perform very well in corrosive media.
Steve Jones
Materials & Corrosion Engineer
Steve Jones
Materials & Corrosion Engineer
You need the back purging to avoid the oxydation of the welding that in certain environments can lead to higher or non expected corrosion.
Above a certain content of Cr in the material, if i remember well 5%, you always need the back puring.
Strider
Above a certain content of Cr in the material, if i remember well 5%, you always need the back puring.
Strider
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