What happened with my 52100?

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godogs57

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Apr 16, 2004
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Evenin' folks.. I have only recently begun working with forging carbon steel blades..been working with 440C, ATS34, et al forever. This forging business is brand new to me. This afternoon I ran up on a problem that I have a feeling is easy to answer - just not for me. I am working on only my second forged blade...52100 steel...during the forging, I had some Journeyman smiths watching over my shoulder earlier on to ensure I got things started out right. This afternoon I flat ground the blade and got ready to heat treat it. I heated it up till it was non-magnetic and quenched in warm/hot peanut oil (suggested by the forgers down south here). Other blades I worked with today turned out just fine, but the 52100 blade only rockwells a 35...what did I do wrong? I ensured that I took it immediately from the heat to the quench, as I was instructed. I am at a loss, but I am sure it was something that probably is quite simple...just don't know what it is. Any help would be appreciated.
 
A couple questions....How do you know it is high carbon steel? and...How did you rockwell test it?...and did you quench the entire blade or just the edge?..

It is posible that it is 1018, because it sounds like you did the quench correct enough to harden it

What kind of rockwell tester was it most testers require the test dimple on a flat spot like on the ricasso...thats why I ask if it was edge quenched or full quenched. Its possible the edge is hard but the body of the knife never reached non-magnetic therefore would not harden.
 
I agree with Bruce, if its 52100 and you took it to critical heat, and immediately quenched in warm oil, it should have hardened. I would be questioning the steel and not my technique. One thing I have had happen, when normalizing some steels it will go to nonmagnetic and when letting cool the temp will fall way below critical heat and the steel will still be nonmagnetic. Could you have done something like that. brought up to nonmagnetic, and let it cool below critical heat but still non magnetic and quenched. Just a throught. If not, then I would try another piece of the so called 52100 steel you have and see if it will harden. Just heat it and quench it, then try a file on it. should skate like its on ice ( no bite).

Good Luck

Bill
 
Did you file test it? If it skates,it's way harder than HRC35.The test may be wrong,or the steel is wrong.
 
Thanks for the suggestions. When forging the blade, I used the small "ping pong ball" sized ball bearings that we all agreed were 52100. I have an unlimited supply of them and the larger ones from a friend in the electric motor repair business...he repairs the huge industrial motors and the repair folks just throw 'em away and replace them with new ones each time a motor is repaired.

I heated it exactly as my buddies do...up to orange pass over it with a magnet and if non-magnetic put back in for just a second to get the color uniform and snatch it out and dunk it quick. They are careful to do the edge quench, but on this one I just lowered it all the way in. I ran the magnet over the whole blade, not just the tip and it was non-magnetic the whole 9 yards.

After cool down I cleaned the blade, flat ground it to 320 grit and placed on my rockwell tester...same 200# tester I have used on all my stainless blades, testing on the flat ricasso area. Afterwards, I ran the file across the blade and it bit...did not skate. It was then that I used the rockwell tester and got my bad news.

Incidently, I my buddies that I am learing this forging from are all Journeyman and Master smiths.. It is really eye opening to see these guys work their magic with the steel! I have all the respect in the world for you folks that forge your blades....Now I have an excuse to take my knifemaking in another direction and see what this is all about.

Hope it was not the peanut oil that I quenched in....lots of guys down here like it because there is virtually no scale to speak of after quenching, and what little you have comes off easily.

Thanks again for all your suggestions...after I get this figured out, I will submit a pic for your critical evaluation.

Hank Hammond
 
Hi Hank. It sounds like you did everything right. I have used many of those ball bearings too and had great results. If it is 52100 you can do it again a couple more times. Ed Fowler is the 52100 king, maybe he will chime in. He swears by the triple quench. He also doesnt use ball bearings anymore because of inconsistancy of the steel. Some are stainless. Maybe you should treat it like 440c? that could be interesting.

I buy my 52100 from Rex Walter same as Ed Fowler. Works every time. Let us know what you find out.
 
Was the bearing or the ball ping pong ball sized ? Could it have been made of a case hardening steel such as 8620 or 4620 ?
 
Hey Mete,

I was using the the ping pong balls...

For what its worth: I read (think it was in Ed's book??) about the 52100 also being in one particular part of the John Deere Tractor...load shaft or something like that...I work with USDA and can get all of those I want from my friend @ church that works with JD...will look it up and make dern sure of the part and perhaps try one of those as well to see what happens.

I'm sure I just did something wrong and don't know it yet...still progressing along the learning curve.

Yep, perhaps Ed can chime in and let me know what's going on...he was extremely nice and cordial to me at the Blade show this year. Heck of a nice guy.

If I don't get anywhere with this blade I just might treat it like it was 440C and see what happens. Tried that with a piece of damascus once but that is a story for another day!

Back to the shop....
 
After believing the 52100 first becomes non-magnetic and at proper temperature leave it soak a short few minutes (5 to 7), quench immediately. See how that works for you. As stated, you can repeat the process until finding the right recipie.

RL
 
I did a search ("bearing aisi" keywords) in google the main material for bearing is 52100 as you stated but if you inspect some are not. 304, 320 316 to 440 SS types are quite common. May be that is the problem...
 
Hank, the John Deere load shafts, also called rock shafts, are made from 5160, and probably the finest grade of that steel available. They make superb knives.
 
Don't read anything into this, I am not looking down my nose at anyone that uses recycled steel, it just isn't what I do...any more.

What you are experiencing is the same reason that I buy all of my barstock. I have been burned before and this is just one way for me to keep one less fly out of the ointment.

After getting burned this way, steel looks to be pretty cheap.

Craig
 
Again, thanks...
Cornered one of my forging buddies this afternoon and with his help I got it right...I suppose I did not soak it long enough, as suggested by Roger, before quenching. Anyhow, second time was the charm.

I appreciate you correcting me Fox on the JD shafts...5160.

Will post a pic when finished assuming I can learn how to post here.

Have a great week
 
This summer I had the time, without distraction, to do some extremely rewarding experiments with 52100. five months produced 5 blades.
The more clean your forging practice, the better the blades.
Stay below heavy scale temp. in order to get the most out of your blades.
Two Quenches is never as good as three.
You need to contact, ASTM, send them some samples of your peanut oil qunench oil and have them do some testing to evaluate the quench rate of peanut oil. That way we would all know what your are working with.
There seems to be no end to the number of thermal cycles (withing certain many times stated paramaters) that can improve performance of good clean and consistent 52100E.
Good luck and be sure to test the performance of every blade, edge flex, cut, strong and tough.
 
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