View Full Version : Got a heat treating question
08-10-2010, 06:13 PM
I was heat treating some 440c I put it in the oven at 1400 and it was in there 20 min on its way to 1880 and I lost power so I just put kao wool oven the kiln and never opened the door let it cool slowly over night now Im ready to treat it do I just treat it as non heat treated ? put it in at 1400 ?:34:
08-10-2010, 06:46 PM
I'm not an expert on 440C, but common sense would tell me that since the austinizing temp was never reached, all you likely got was some grain refinement and annealing done.
I would start the heat treat over, as if you were working from annealed stock.
Not sure, but I think it would be fine to treat it as usual. Maybe someone else will have a better idea.
08-10-2010, 09:04 PM
A.W.Basicly what you did was a sub-critical anneal.Just staart from the beginning and you will be fine.
08-10-2010, 09:56 PM
I think my toaster oven malfunctioned brcause the blades were very hard/brittle oh well at least they were small. It was the first time I used the aluminum plates. I was really just testing anway
A.W. What temp did you temper at? You can retemper at a higher temp if they are to hard, just raise 25 degrees above the original tempering temp and do 2 hours at the higher temp.
08-11-2010, 07:54 PM
how long after the treat can you temper and it still turn out ok? I know that as soon as it gets to room temp your supposed to start the temper but under the circumstances will a day or 2 render the blade useless?
A.W. if I understand your question, correctly, you are talking about the first temper after the quench. If so I realy don't know if it would be useless or would just increase the risk of cracking during the temper, someone else will have the answer to that one. If you mean the added temper of 25 degrees, after the initial temper, you would be fine to do that anytime.
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