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How are the blades set and supported in the oven? If they are too close to a coil, they will warp. OK, I have been HTing 01 for over 15 years. If I do not do a separate stress relief, my blades warp, and sometimes even then slightly. Per Kevin Cashen's advise, and advise from Robert Cella years ago, I stress relieve for an hour or longer, after the temp reaches 1200?. I do this the day before I do a programed HT, and also coat the blades with ATP641 for decarb protection. I start the main HT with the blades mounted edge up in slotted fire bricks, in a programed cold oven, and it preheats the blades at 1250? for 30 minutes, then goes on up to 1400? for 15 minutes, which is done only to let the oven catch up and equalize. Then the temp goes up to 1475? for a 20 minute soak before quenching in 130? Parks AAA oil. I will add that my blades are finished ground and polished to a 220grit surface before HT. My Evenheat oven does not over shoot temps. It under shoots, and takes as much as 10 or so minutes to level out in the upper temp ranges. If you never ever get at least slight warping with 01, you are running thick unfinished blades, or you're just not trying hard enough. 01 can be hand straightened for about 6 to 8 minutes out of quench, and with some blades as long as 10 minutes out. Stress relieving greatly reduced my warping problems, but I've never had blades warp in the oven. Only in the quench.
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