pro mod steve
- pro mod steve
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Joined:Wed Mar 31, 2010 12:47 am
I have read to pre heat CM tube in cold temperatures but can any one explain technically why?
The tube should be at the very least 70 deg. before welding. As you know heat control is a critical factor in welding CM. As for my 2 cents worth, hydrogen embrittlement is the issue . There must be suffucient heat for a sufficient amount of time to allow the hydrogen to diffuse fron the HAZ. If not, CRACK. And we all know that CRACK kills.
Jim
Pipefitter/Weldor out of Local 396
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Pipefitter/Weldor out of Local 396
Millermatic 252
Dynasty 200DX
Maxstar 150 STL
Spoolmate 100
Hypertherm Powermax 85
Miller Digital Elite
JD2 Model 32 Bender
Emerson 7120 Horizontal/Vertical Bandsaw
Oxy-Gas Torch outfit
Generac XP8000E Generator