By -
Date 03-22-2005 02:44
Thank you, Sir, for your comments. They are very well taken and very true. I guess that since I work for the company that developed and manufactures both the 2205 and 2507 (UNS 31803 and 32250 duplex and UNS 32750 Super Duplex) I try to be very cognisent of the levels of carbon. Since the max. carbon content of a duplex material is 0.02%, both Duplex and Super Duplex, and the max. carbon content for FCW filler metal is 0.04% for 2209, then you can see why the carbon has to be monitored so closely. Naturally, the 2507 Super Duplex filler metal is a propritary product so it is not addressed in A5.22-95, only 2209T0-1 or 2209T0-4. As far as the 410 was concerned, I was only trying to make the author aware that the carbon content of the base metal he was using, especially with no formal PWHT. is very critical when determining a preheat temperature. Of course, we did not all the facts of service conditions and other critical conditions the part might experience, so you and I both tried to give good practical advice based on the limited information we were given. As we discussed earlier, although the carbon pick up might be very little when using FCW, sometime ANY is too much. So, to take that totally out of the equation, 75/25 is normally recommended when welding Duplex or any stainless steel where the carbon content is right near the maximum limits. Thank you for your response as it was most interesting and true. I really enjoyed our discussion. You, too, seemed very knowledgable in stainless steel welding. Maybe soome time we can discuss other corossion related items. Thanks again...
Peace B2U
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