Rockwell C scale

Bluntcut, just to kinda re hash what Willie mentioned, that we need to first get carbides evenly dispersed and then reduce the carbide grain size. This is done by normalizing at around 1650F, maybe a short soak. Of course....this will blow the "grain size" up more than we want.....so we now must refine that grain size by thermal cycling, followed by air cooling. On hypereutectoids....air cooling is the slowest we want. No vermiculite, no wood ash, just still air quench. Quenching in oil between thermal cycling is no problem at all. As a matter of fact....grain size might be reduced even MORE by using oil quenches between thermal cycles....but at a risk of micro fracturing in the matrix. Maybe...maybe not. Quenching in oil during cycling might work best for steels with a touch more alloying....like 52100. So after the carbides are evenly dispersed, we go to thermal cycling to make the "grains" smaller. 1550F, cool in air or quench in oil. 1450F, cool in air or quench in oil. 1400F, cool in air or quench in oil. These three steps (4 with the first normalizing heat) will refine the grain extremely well. We can now go straight to hardening, or perform a spherodize anneal if grinding/drilling needs to be done on the blade. (If you have control over temp, 1250 for a couple hours works very well. If you can do programing and ramp control....go from 1400 down to 1250 at 50 degrees per hour, then hold at 1250 for a couple hours). If you want to go straight to hardening....Willie and Don are using 1460F as the sweet spot temperature, and soaking for only a few minutes....not 10 or 15 minutes. As long as the quench medium is right for the job, like Parks 50, DT-48, Brine, and there is plenty volume of it, you should get those 66-67 and, if you're like Willie......70.5!!! (that high of a number sure is interesting). I think Bluntcut mentioned superquench. Not sure about that stuff. I had to look that up right now to see what it was. A homemade brine/soap solution it looks to be. Damn I wish I had a RC tester!!!
 
I have a new coupon thermal cycled and ready for austentizing to see if I can repeat the unusual high single reading. I'll test the piece 20 or 30 times in different areas to see if it happens again. I also mailed a piece to Don to see what he gets.
 
I've posted ht details my W2 thread. Over all (experimented steels, relied on my few-drops-in-metallurgical-bucket), experimented ht params: yes/no quench between thermal, hot/room hammer strikes, high(forge heat)/regular normalize temp, formal/quick spheriodize, park50; mccarmaster 11secs oil; canola; water; brine; superquench; air; plates aluminum & steel; and combo thereof.

As for super quench, I've successful done so and with good performance result for: 52100, 1095, W2, CruforgeV, White#2, 15N20 and few more. I've a thread on this too and most here gave up on my stubbornness:foot: on this subject matter as well, including a super patience master KM - Stacy. Keep in mind while search in the internet, count how many other maker/mfg that successful super quench high & ultra-high carbon blades/tools -> about zero. Legit to ask/wonder why? or wonder on the level of control elements in solution in order for the steel to withstand this transformation shock. Temper hardness curve will be quite different than normal ht.

I repeatedly state that my failure in getting good wear resistant using Aldo W2, could be because my lack of experience & skills & ht method. Try to be fair and truthful while sharing at the same time. Many times I mentioned how great Aldo 52100, 1095 & other steels are for my uses, except/truth having a small difficulty with his W2.
 
Willie, be sure to let us know what your results are with the second coupon test! I'm curious as to your results. About the superquench...I have no experience using it, so I couldn't qualify an opinion on it very well. But I would recommend not using it, and going with something more reliable and repeatable with consistent results, as commercial quenchants are formulated that way. But there certainly isn't anything wrong with experimenting and having fun! Along those lines...I try to offer the best advice I can, with what little I know. Just recently, on another forum, a guy was asking if he could add carbon to a knife steel...carburizing. My reply was just a recommendation, that he forget the idea and go with a known steel with the carbon content he wants, that the process to carburize steel is quite a process, and generally isn't something that can be readily done in the average shop. A reply was directed to me that basically said, your opinion sucks and you shouldn't discourage someone from trying/learning/failing. OK then. It was just my opinion. I don't jump on someone because theirs is different than mine. Ok...had to get that out. that guy ruined my day.
 
stezann said:
Admit, you are just jelous because he's goin' to create the ultimate cutter and you are still hanging around with those miserable known steels ;)
Click to expand...

He he!!! You're right! I should start buying 1018 from now on and crush up diamonds, pack them around the 1018, and stick it in the fire for a week. I'll have 150CrW5V2000Mo3Co7. And that extra carbon!!!!
 
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