- Joined
- Aug 5, 2014
- Messages
- 213
Hey everyone 
So today I forged out a nice gyuto from a bar of 24mm 52100 (suj2 to be exact but nearly identical). After forging was complete I went to the electric oven and did a normalization at 1600F and thermal cycled down at 1500 and again at 1400.
Previously I've done a spheroidal anneal by soaking at 1250F for 2 hours with good results, but after reading about Kevin Cashen's method of annealing I decided to go for that. The process is soak at 1375F for 45 minutes then ramp down to 875 over a period of 10 hours.
The last time I checked the oven, it had already soaked at 1375 for the 45 minutes and was in the ramp down phase, down to just under 1300. When I returned home hours later, the set temperature was at around 1100 but the actual temp was around 750 meaning that the oven had stopped cycling (investigating cause now). This means that at some point below 1300F, the oven stopped heating and the steel cooled down with the oven.
My question is, aside from affecting machinability is there going to be any negative effect from the faster cooling down due to oven shutting off? I tested drilling the tang and it's nice and soft already.
My guess would be that since all heat treatments were done at progressively lower temperatures that everything should be locked in place...and as annealing doesn't go above critical before cooling, shouldn't be any detrimental effects right?
Thanks in advance for any help!
So today I forged out a nice gyuto from a bar of 24mm 52100 (suj2 to be exact but nearly identical). After forging was complete I went to the electric oven and did a normalization at 1600F and thermal cycled down at 1500 and again at 1400. Previously I've done a spheroidal anneal by soaking at 1250F for 2 hours with good results, but after reading about Kevin Cashen's method of annealing I decided to go for that. The process is soak at 1375F for 45 minutes then ramp down to 875 over a period of 10 hours.
The last time I checked the oven, it had already soaked at 1375 for the 45 minutes and was in the ramp down phase, down to just under 1300. When I returned home hours later, the set temperature was at around 1100 but the actual temp was around 750 meaning that the oven had stopped cycling (investigating cause now). This means that at some point below 1300F, the oven stopped heating and the steel cooled down with the oven.
My question is, aside from affecting machinability is there going to be any negative effect from the faster cooling down due to oven shutting off? I tested drilling the tang and it's nice and soft already.
My guess would be that since all heat treatments were done at progressively lower temperatures that everything should be locked in place...and as annealing doesn't go above critical before cooling, shouldn't be any detrimental effects right?
Thanks in advance for any help!
