Stock Removal 52100

Jason Wilder

Well-Known Member
I have read where the forging requires multiple quench cycles but haven't read anywhere about the need for the multiple quenches for stock removal. No doubt that's because before now 52100 HAD to be forged. But thanks to Aldo, that's not true any more.

Suppose I got some thin 52100 from Aldo that was already the thickness I needed and only needed to profile and grind to shape... How would the heat treat be different from if I were to forge it?

Thanks,
Jason
 
Ok, even with stock removal I would normalize the steel. Stresses can build up during stock removal and you don't know how much the steel was stressed in previous handling. By the way, rolling a round bar of steel into a flat bar is still forging. Multiple quenches will still do the same thing in stress and grain reduction but it causes the phase change to happen more quickly and, in theory, creat even smaller grain. The down side is that it can cause microscopic cracking where plate martensite intersect. All steels with enough carbon to harden into a usable blade will form at least some plate martensite. A steel like 52100 with approximately 100 points of carbon in it will form all plate martensite and increase the likelihood of forming microscopic cracks. This can't be avoided entirely if you are forming martensite to harden the steel but if you are quenching three times to refine grain structure then that is two additional opportunities to creat small fractures in the blade. Of cource if we're talking about an air quenching steel multiple quenches to refine the grain can't be avoided.

As far as how much difference is there in heat treating a stock removal blade and a forged blade, not much. Of course with forging multiple normalizations are pretty much mandatory. With stock removal you might be able to get by without the multiple normalizations but, other than that, the heat treating would be the same.

Doug
 
jason

52100 is a tricky steel to do at home without a temp controlled forge or HT oven...you got anyone near there that can do it for you?

IIRC you heat to 1550 and hold for 5 minutes and quench in a medium speed oil and that should take care of any need to multiple quench

IF you using a torch or coal forge, you prolly gonna have to go with a multiple quench...err at least that is what i have gathered to get the performance difference out of it...
 
Well, for starters, everyone knows forged blades are inferior, because they have been heated to temps that a stock removal guy would throw in the trash. If that doesn't create enough stress, they bash the hell out of them with hammers. They think they can make all that abuse right by 'normalizing' - kind of like CPR, which we all know doesn't really work.

You can forget triple quenching - soak for 15 minutes at 1475 and quench in a fast oil. You'll get mid sixties RHC. Temper as desired

Now, its probably obvious, there is a little good natured fun poked at the smiths here - but the HT works. Try it. Aldo's 52100 flat stock is sweet!
 
I have a forge, HT oven, and proper quenching oils. I was just wondering if it was necessary to go through the multiple quench cycles if I chose to grind rather than forge.
Thanks,
Jason
 
I have a forge, HT oven, and proper quenching oils. I was just wondering if it was necessary to go through the multiple quench cycles if I chose to grind rather than forge.
Thanks,
Jason

No - whether forged or stock removal, normalizing may be beneficial, but lower temp and longer soak will eliminate the need for multiple quench. I learned this recently myself and it has been working well.

Rob!
 
Ok, now that we've heard from the pur-vey-or in our midst:biggrin:, Rob makes a good point. It's best to keep a hypereutectic steel below upper critical and extend the soak time to prevent grain growth. Actually, that is what some people get when they do multiple quenches, just in stages. They don't give the carbides a chance to disolve adiquately to release their carbon into solution and when they quench they trap what has disolved into the martensite. With each successive austinization and quench they disolve more carbon into the austinite until they have a good level for proper hardening. A 5-10 minute soak at below 1525 degrees will give you a good carbon level in the austinite without having to risk micro cracking. One thing about 52100 is that you will not disolve all of the carbides in it unless you just about melt the steel but with 100 points of carbon, or there about, there's still plenty to get optimal hardening from it.

As far as heat treating goes, I austemper at 430 degrees. That gives me a little more hardness by forming probably around 25% martensite.

Doug
 
Aldo's 52100 is nice stuff. Once you get the H/T down you'll love it. I do a couple of 1200 degree cycles to relieve stress and refine grain. I harden at 1475 (don't go above 1500 to keep the RA down) and quench in 11 second oil. This should get you 66-67 HRC. Start your draw around 400 and work up to what works best for you and your equipment. After you test a blade or two let me know what you think.
 
ok I am confused

going above 1500 gives you more RA? I thought you had to get into the 1600's for that to happen

its listed as heat to 1475°F to 1550 f adjusting for RA...makes sense I guess to go slightly under that

you could do both sinse you has an oven and the correct oil

do one with a 5 minute soak at 1500

do one bringing to 1500 and immediately quenching and repeat 2 more times

see if there is an improvement
 
The 1475F temp is according to Kevin Cashen. I have also heard Ed Caffrey talking about keeping it below the "saturation point" when austenizing.
 
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The 1475F temp is according to Kevin Cashen. I have also heard Ed Caffrey talking about keeping it below the "saturation point" when austenizing.

Ok got ya...I never really thought about it, but those temps dont give you much wiggle room...I got some stock removal 52100 in trade but havent used it yet since I has no HT oven...might have to try triple quench for giggles
 
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