reheat treat 440C

J

J.D.

Joined
Feb 12, 2006
Messages
342
I am working on 2 fillet blades and one warped bad in the quench, about
3/32". I think, I know what happened, I placed this blade on the bottom plate while I was getting the other one out of the oven and placed it then put the top plate on, I think this caused uneven cooling due to one plate on the bottom and none on top, for about 15 secs. My question is, can 440C be reheat treated, and be ok? Or do you have to anneal it first? it has been tempered and ready to clean up and finish.
Thanks
Dale
 
Dale

I'm not sure your theory is correct. I routinely plate quench up to six blades at a time - often taking 30 - 40 seconds to get them in place before placing the second plate. Warping is very rare.

440C can be re-done, but don't count on the warps coming out. Think of bending a strip of Plasticine. The outside of the curve is stretched and the inside is compressed. They don't go back into place well. :(

Rob!
 
Rob, thanks for the advice, the reason I came to my theory was it even warped into the tang where there was no grinding done, this is 1/16" thick stock. I really have nothing else to base it on, so my theory maybe incorrect. As far as the warp coming out, I was thinking of heating to a lower temp, say 1000f and straighten it, (Cruciable data sheet says that it scales at about 1400f depending on atmosphere) then wrap in foil and heat treat, after cooling to room temp. What do you think this would do? Would it be worth trying or should I start over on this one?
Thanks again.
Dale
 
Dale
1/16" stock will just do that some time.I've jus started grinding mine after H/T.
If the warp is not real bad place it between a couple of pieces of 1/4" stock,C-clamp it down tight and put it in the oven at 400 deg for a couple of hhours.Some time that works.
Stan
 
Thanks Stan, I will try that. I may have to do my grinding after HT on this thin stuff, I hate that.
 
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