Wow. This WHOLE time I've been soaking W2 for 10-15 minutes. This AFTER normalizing 1650F, air cooling only, thermal cycling down as we do, air cooling only. No anneals, all this done after machining. Matrix should then be fine pearlite....and I am soaking that, and I should NOT be soaking that, huh?
But 52100 and O1 are different stories, or are they? Because of the alloying, the soak is employed, if we're sticking to the 1475F aus temp and starting with fine pearlite as well?
This whole time I've been under the impression that any hyper eutectoid steel should get a soak, if hardening in that sub 1500F range. Even 1095 gets a soak, when maybe it shouldn't (austenitizing a fine pearlite structure). So if one had spheroidized 1095, they normalized and cycled it, air cools, with fine pearlite, and they harden at 1475F with NO soak, what makes that steel any different than 1084? Assume the answer to be the pro-eutectoid cementite left as carbide at 1475F, which gives some added wear resistance over 1084, even tho both steels only have ~0.7% C in solution. Same with W2....the difference is finer possible aus grain (vanadium), a little tougher than 1095 (chromium), and a little extra cementite?
But with O1 and 52100, there is some decent alloying. To have the alloying advantage, one must either use temp or time. Temp being RA problem maker, while time is much less of an RA trouble maker but still gets the alloying advantages.
Does that sound right, or what am I missing? Thank you so much for all your help with this HT stuff, Kevin! Would be nice to buy you a few drinks someday!