Bulk heat treating SS?

[LCoop]

Ok SO I'm set up for heat treating with a PID electric kiln and a PID controlled tempering oven to do SS. For some odd reason, delays in shipping from suppliers etc I've ended up with a bunch of SS knife blanks ready to heat treat complete with DN dry ice sub quench. I've always went straight from heat treat to DI with no snap temper.

In a effort to maximize the DI, I can effectively heat treat all of the blades I have BUT my problem is my present PID controlled tempering oven can only do maybe 8 knives at a time.

SO should I, with the remaining knives I have coming out of DI that I can't run through my precise tempering oven be put in a my kitchen oven set at 200 F to stress relief? Before I can actually run them through my PID tempering oven at correct temps and times?

For the record the SS is CPM154, 440C and AEB-L

 

[JTknives]

All thoes steels are stable and should not give you any cracking problems. Why can your tempering oven only do 8 knives at once? I have not found any problems with there being a delay between cryo and tempering. I know I know, “Oh thy will explode if you look at them funny”. Only steels I would really wory about are high carbon steels that where fast quenched.

Just think about it, it’s not uncommon for these steels to sit in cryo for 24hrs. I’m not saying to wait a week befor tempering but it’s not a HUGE rush.

I trust a kitchen oven about as far as I can throw it. I have even stronger feelings twords toaster ovens (facepalm). You can get some real large swings in temp. Only way I use a kitchen oven is with a long warm up and a big steel plate in it. Talking like 3hr preheat or so.

How many knives are we talking about here? I do large batches quite often and in fact just finished a batch of 27 kitchen knives out of Damasteel. I allways do the first temper as a batch at my set base point temp. No mater the steel it gets this temp. Then all the knives get hardness tested and a tempering schedul is asigned to them individually. Temps are adjusted according to the hardness desired compared to the hardness after the base temper. But I do this for a living so to speak so I am very nit picky. If you have used my service you might notice the large number of hardness test marks. We hardness check at every stage. I’m a bit obsessed with the testing lol. Actualy looking at getting a second hardness tester. Wait that would be a 3rd tester “hangs head and walks out”.

 

[LCoop]

Ok I have a table top convection oven that I have rewired after having added thermal mass that is PID controlled that I've tested to be accurate. But I can only put maybe 6 to 8 blades in at a time.

Your analogy of they could be in a dewar for 24 hours makes sense. I just keep hearing all of these horror stories of AEB-L doing crazy stuff during heat treat.