How to heat treat THICK 52100???

R

rjfm1972

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Jan 13, 2013
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I have successfully heat treated 52100 that I forged to 3/16" thick or less. But I have been trying to heat treat a few .260" thick blades, and I just can't seem to get them harder then RC55 after Quench. I am using Mcmaster Carr 11 second oil. I tried water and got it over RC60, but also got micro cracking. Is there a trick to treating this thick of 52100? I have also tried the triple quench method with no better results. Any help would be great!
 
How do you know it's 52100 ?

What is your heat source, how are you controlling the temperature?

How long is your soak and at what temperature?
 
Its 52100 from Aldo. I always work with known metals. I have a vertical propane forge that I have heat treated 1095, 5160, 52100, and aeb-l successfully in. I have soaked it at 1550 for approx. 8 minutes, and have also done a triple quench with temps from 1600 to 1500, and still no luck. Its almost as if the surface can't cool fast enough because its so thick that the inside is keeping it hot. I know it can be done. Someone must be successfully heat treating this stuff in this thickness. I just need to know how.
 
I had a similar problem with some of Aldo's steel. you can try this. It is a triple quench. start by soaking at 1700 for 20-30-min remove and quench in 150 degree preheated oil. agitate the blade as you quench. I would let the blade sit in the oil for ten to fifteen minutes then remove it and clean. Nexte reheat the blade to 1550 as fast as you have the means to do and quench as soon as the blade reaches temp again preheat your oil and agitat the blade in the oil. leave the blade in the oil at least until the temp of the oil starts to fall. remove the blade and clean the oil off. now reheat the blade to 1475-1500. again reheat it as fast as possible and quench. temper to desired hardness.
 
I'll give that a try Bill. I've never heard of soaking for that long at that high of heat before the first quench. I know the two following quenches will help shrink the grain size and thought that maybe I should bump the heat up a little. I'll probably do it tonight and let you know how it worked out late tonight or tomorrow. Thanks for the info.
 
I gave up on 52100 a long time ago. Just didn't work for me.

There sure is a learning curve to get the best out of that stuff!
 
Could it be your quench oil? I use Parks AAA and haven't had a problem with 52100. Seems it's suppose to be a little slower than McMasters 11 second, but I'm not sure. Might be worth checking out. I'd also double check the temps you mentioned as well as making sure your pyrometers are reading properly. Seems there was a thread here back a few months ago where a faulty reading pyrometer was causing some problems.

What's the temperature of your quench oil at the time of quench?

BTW, thank you Mr. Burke for throwing that HT recipe out there. Just like baking/cooking food, I'm always up to try a new recipe!!
 
This is an issue with that batch of steel. It isn't anything wrong with the steel, just that it has already been through a good HT to make it easy to work. With the standard book HT, it won't harden worth a dang.A really superior HT for this steel was worked out by Kevin Cashen and several other metallurgists. The discussion about this and the solution can be found in several threads on several forums. Here is one:
http://knifedogs.com/showthread.php?26777-heat-treating-52100

Give Aldo a call, he can pass on the details about how to get his 52100 hard as woodpecker lips.
 
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As I stated I had some problems with some of Aldo's 52100. I ended up doing the 1700 soak to insure that everything got into solution then the two 1475 degree quenches to refine the grain. this worked very good when I couldn't get a decent hardness out of it with a "normal " hardening procedure. Later speaking with Aldo at blade show he told me to try a high temp soak like this. If I had known about it I would try the method Kevin outlined in the other thread. I don't care for the long high temp soak because it promotes grain growth and I would prefer to avoid it rather than try to recover from it. thanks for the link Stacy
 
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After reading the thread Stacy linked above I played with Aldo's 52100 and here is what I do with it.
1. Soak @ 1650 for 5 minutes and air cool to black.
2. Soak @ 1550 for 5 minutes and air cool to black.
3. Soak @ 1450 for 5 minutes and air cool to black.
4. Soak @ 1475-1480 for 20 minutes and quench in McMaster-Carr 11 sec. oil.
This procedure consistently gives me an as quenched hardness of 66-67. Usually 66.5. I temper 2 times at 2 hours each. I temper anywhere between 375 & 450. This is what works for me and my equipment. If you try it let me know how it works for you.
 
So here's what I decided to try. Per Mr. Burkes advice, and some additional reading on the links Stacy provided, I soaked it for 30 minutes at 1700 degrees. I saw one test that went as high as 1800, so 1700 sounded good. I quenched it in pre heated oil, and cleaned and re-heated to 1600, quenched, re-heated to 1500, quenched. I then cleaned it off, polished off most of the de-carb, and tested as quenched. Now keep in mind, I am using cheap hardness files from Grizzly, so I am not sure of the accuracy. But the 55 file will not scratch it, but the 60 will. So still not as hard as I was hoping. So I decided to finish off the process, and tempered at 325 for 2 hours, soaked in an acetone/dry ice bath for 1 hour, and tempered again at 350. I am having it properly tested tomorrow to find out EXACTLY where its at and I will post tomorrow after I get results. One quick question for everyone here. I am quenching my blades in a 2 1/2" diameter stainless tube. The oil gets so hot after the quench that I dunk it in a 30 gallon tub of water afterwards, and it actually sizzles on the outside of the tube. Is this my problem? My quench tank too small and oil heating up too fast for a proper quench? (I do swap the oil out between quenches for anyone who thinks I'm an idiot ;o))Anyways, again I will post hardness test results tomorrow.
 
In my opinion you need at least a gallon of oil for a proper quench. My tanks hold about 4 gallons.
 
If the blade tests too soft,I am going to try another blade this week with a 5 gallon bucket of oil. If it works, problem solved. Matter of fact, I am going to try that anyways and see what happens. I suspect it may be my issue.
 
Yes, your quench tank is too small, even for one quench.

Also, if you are going to have the blade tested (hardness) you need to test a flat parallel piece to get an accurate reading. Testing a bevel will not be accurate.

Just for conversation, I'm getting 67-68.5 Rc as quenched from my W2 and 62 Rc after two one hour cycles at 450f. This stuff is out performing all other simple carbon steels I've used over the years.
 
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"Just for conversation, I'm getting 66-67 Rc as quenched from my W2 and 62 Rc after two one hour cycles at 450f. This stuff is out performing all other simple carbon steels I've used over the years."

Sorry for thread drift, But i have found pretty much the same thing with the W2 that Don has. I tried making mandrels to Rc test on the blade bevels but could not get a accurate reading. I ended up taking a donor knife and grinding it to .060 thick and tested it and as quenched it was 68Rc and after following Don's temper I was at 63 RC. Now I will use a small piece left over from each batch of knives for testing along with testing on the tangs. That W2 he has is awsome, awsome stuff. I am glad i made sure I got a little bit from him to keep me busy for awhile.
 
Mike, the reason I got a hardness tester was Tony Bose. I was heat treating W2 blades for him (talked him into using some:)) and when he got them back they were 63-64 Rc. He said "Don get a harness tester". I said, yes sir! :D
 
Don Hanson III said:
Mike, the reason I got a hardness tester was Tony Bose. I was heat treating W2 blades for him (talked him into using some:)) and when he got them back they were 63-64 Rc. He said "Don get a harness tester". I said, yes sir! :D
Click to expand...

Good as any reason to get one! Hardness testers can be fun and they can kill your ego I have found. But they sure can eliminate the guessing, that's for sure.
 
mike malosh said:
Good as any reason to get one! Hardness testers can be fun and they can kill your ego I have found. But they sure can eliminate the guessing, that's for sure.
Click to expand...
An educated guess will get ya by, but it's better to know. Tony told me, "ya can't know what ya don't know" :D
I've been testing stuff all around the shop and have been surprised a few times.
 
I got the results back from the hardness test today. The good news is, my files were pretty much spot on as far as what I was guessing they were telling me. The bad news is, what they were telling me was not what I wanted to hear. The blade tested at 54-56 RC. Thats after 2 hours at only 325, a 1 hour acetone/dry ice bath, and 2 more hours at 350. I am very dissapointed. Its a somewhat useable blade still, so I may just finish it and give it away to someone. I am going to try a fresh blade tonight in a much larger quench tank and see if that makes a difference.
 
Here is a picture of my failed mission. Fortunately I have 5 more just like it to practice on. LOL

 
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