qt 400

Hello, would anyone have any information on welding qt 400 using m.i.g.
material thickness is 3/8" thick, I was wondering if a preheat would be
necessary because of the hardness. Thank you........Ed
Reply to
Ed Atyeo
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I am not sure about the carbon equivalent of QT 400 but that would be the place to start. You often can get that from your supplier. Did it come with a mill certification? The hardness isn't a concern. what is the amount of carbon in the alloy I am guessing that if you preheat to 100 C it should be good enough. 3/8 thick will often allow you put minimal preheat input. To test you might try setting up two pieces of scrap in a Tee and do a fillet about two inches long. Snap the assembly open and examine the fracture. If you have the weld tearing out the parent metal you need preheat. Repeat the test with preheats until you don't have tearout. I notice that you posted about welding to stainless. I am wondering which stainless wire alloy you chose. 309??? 312?? Randy
Reply to
Randy Zimmerman
Thanks for the info Randy, the wire I will use is for the s.s.309 and I think I should be able to get the mill certification.
Reply to
Ed Atyeo
Once you get your mill certs, you can use this to calculate preheat to british standards.
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Reply to
Rich Jones
Looked it up today at work... No worries. Preheat is room temperature until you reach 4 inch thicknesses. Randy
Reply to
Randy Zimmerman

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