Andre Grobler
Well-Known Member
Well either deep freeze -20C or LN for -120C… yes, what Landes said made sense for cold treatments, you want to be going down or up in temp almost all the time. Except at lowest points, so that you convert retained austenite all the time, the temp must not sit still where ra can stabilise. So first temper sits at 150C or 300F and second at 350F for stainless, for carbon steel, i sometimes use -20c because i refine grain a lot and our quench oils are not very fast over here, so as a precaution it goes into the deep freeze, but i dont bother with a second -20c between tempers, unless i call it a day before second temper