Time from quench to temper

[luc]

Hey all,
Quick question, I just started working with Stainless (ats34) and was curious how critical the time between quenching (with plates) and getting it in for tempering is?
I'm using an Even heat furnace and with the door open I think it takes around 1 hour to get below 400f. For smaller blades I could snap temper them in my toaster oven, but anything over about 10.5 oal is out.
Thanks.

[mete]

Quenching stresses can be very high, enough to cause cracking . Therefore tempering should be done immediately to reduce those stresses....Can you sneak it into your wife's kitchen oven ?

[luc]

Thanks,
How do the rest of you guys with one furnace handle this problem.

Would sticking the blades in Vermeculite after the quench while the evenheat cools down help?

[R. D. Finch]

Lucas

I use a toaster oven ,pre heated to 300 dregees, to place my blades in after they cool down to room temp, for 2 hours.

[rashid11]

Called "Euro-toaster" or something like that. You should be able to stick
18" long blade in there easily. Beware - there're 2 varieties: a more expensive
one with smaller chamber and the $20 one with a larger one.

It goes from 150 to 450, has a timer, 2 heating element (bake/broil) and
what else can you ask for in a $20 thing

[RJ Martin]

I would not trust any toaster type oven unless I had checked it with a thermometer or digital panel meter first. Same goes for the kitchen oven, and your even heat kiln. Trust nothing-I have seen them all be off by surprising margins, particularly the kilns at low temps.
But, if I trusted the even heat the most, and needed to kill an hour before it cooled to tempering temp, I'd pop the blade in the kitchen oven at 300-350F. It will de-stress the martensite and won't affect the higher temperature temper that follows.

BTW, I have never had a blade crack from excessive stress when press quenching, nor have I had one shatter when rockwell tested immediately after quench. Not that it can't happen.
Generally, all my SS blades go immediately from the plate quench into LN2, and I have never had one crack in there, either.