How to Heat Treat 52100

[Larrin]

It is very easy to prove that one's heat treatment is superior in terms of toughness. I don't charge to test the toughness samples.

 

[HSC ///]

Nat you are creating friction again. Several people went to a lot of work and expense to do this article. Then they shared what they found with everyone free of charge. I just reviewed the article and there was nothing that said that it was the only way to do the heat treatment. The article was well written with full disclosure of how they acquired the data and how the steel was sourced. You are disputing the results of the test with far less careful data. Where I am going with this is I'm trying to explain to you why you are creating a lot of friction in hope that you will try a different approach. So when you make comments like that and don't have robust data your information is very suspect and because of that your motive does not seem friendly. Your proof is that someone that you are the only one who has had contact with is getting a different result. That's not data that does us any good. If you read the articles more carefully you will notice that where the steel is sourced and the condition it's in gives different results. From some of the post I have read I gather that different recipes because the steel that is readily available a different than what was available in the past. Remember that most of us are in north America and are getting our steel from 2 suppliers. There is a effort to get them to supply MTR's and its common knowledge that if are using a different batch. It's the responsibility of the one heat treating to sort through the data and see what works for them. If you want to share what you have learned no one is complaining. But if you are going to just challenge a article for no reason people are going to call you a troll. Not only that but we are getting some of the best knife making data and if Larrin and the others become frustrated because they are getting attacked they might stop and that's bad for all of us. Also when people are spreading information that is wrong it creates confusion. I have learned from my wife that different people have different communication styles and I know that you keep saying that that something is being lost in translation but you keep coming off as rude. Its probably best to change. If there is something that you don't think adds up why don't you try asking instead of making a statement. I personally think its pretty cool that we have access to a metallurgist. Personally if I was getting push back by someone with a degree in metallurgy and top knife makers I would take a look at where I am getting my information. This is a cool site why create drama.

very very well said, thank you for that

 

[Willie71]

I had a discussion this past week regarding 52100, W2, 1084, and 1095 with another Canadian maker. He knows about the work we are doing with the testing, and used protocols we have tested to work well. His results are consistent, and top notch. Following these protocols with the data behind them is sound practise. If new testing shows other protocols to work well, or better, that data will be compiled, and also recommended.

I have both NJSB and AJS 52100 here, normalized and cycled, or DET annealed to see if each source responds better to either process. Since our samples used a mix of sources, and annealing procedures, this is needed to complete the picture. I will be doing medium speed samples as well, since fast oil/water is only recommended for the lower austenitizing range. We need to compare apples to apples. There is almost 0.1% carbon difference between different sources. That can make quite the difference.

 

[Willie71]

I use molten salt as quench media so the as-quenched hardness will be lower than normal oil quenching. But as I said I got 61 after 400F tempering with my protocol. From what I tested 1475F HT will give lower hardness and this has been confirmed from Larrin's article.

Have you made samples with this process for Larrin?

 

[Storm W]

Not quite free, some of us support this work through Patreon because we see how important it is.

We all should be helping out with this. I'm not working right now and I feel horrible for freeloading. A well written article is a ton of work and some of this cost money too. The fact that we can croud fund research into knife specific things is awesome. Its very likely that looking back from 10 years later we will see a trend of a large increase in performance of hand made knives do to freely available research.

 

[Natlek]

I use molten salt as quench media so the as-quenched hardness will be lower than normal oil quenching. But as I said I got 61 after 400F tempering with my protocol. From what I tested 1475F HT will give lower hardness and this has been confirmed from Larrin's article.

I know about that molten salt nothing , you can try to start your thermal cycle before quenching with much higher temp then 1650F ?Maybe yu can start with forging temperature .........?? If you don t get 66 HRC on 1475 F after quench for me it is not good .........

 

[hugofeynman]

I use molten salt as quench media so the as-quenched hardness will be lower than normal oil quenching. But as I said I got 61 after 400F tempering with my protocol. From what I tested 1475F HT will give lower hardness and this has been confirmed from Larrin's article.

My favorite kind of heat treatment (although I’m no knifemaker, neither a Metallurgist!). That way, you can get some bainitic structure, if you want. And molten salt has the lowest temperature variations inside the pot, all places of the salt are (almost) exact same temperature.

 

[Metalhead0483]

Thanks for doing all that leg work. That's an impressive read, and something I will reference in times to come. Someone mentioned patreon? What's it under?

I have become a huge fan of 52100 in the past year or so. I've been using it for a lot of smaller forged slicers, starting from thinner round bar. I realize I don't get anywhere near the maximum possible from the steel, but even doing my relatively simple backyard heat treat I have found my results to be VERY satisfactory. Someday I'll have a more sophisticated setup, and be able to really get going, but for now, it works for me

 

[comet_sharp]

I know about that molten salt nothing , you can try to start your thermal cycle before quenching with much higher temp then 1650F ?Maybe yu can start with forging temperature .........?? If you don t get 66 HRC on 1475 F after quench for me it is not good .........

You sir sound like a bad troll. Salt quench auto tempers for toughness.

 

[Ocelot85]

It should be pretty obvious that N Natlek is a troll, he always has been one so I doubt it will change. What isn't obvious is why he's been allowed to continue coming here for so long. People act like because he isn't totally fluent in English that something is lost in translation and his consistently arrogant and rude behavior is just part of his poor understanding of the situation. I would have to say that he understands what he's doing pretty well, when he consistently target's Larrin , @DevinT, @kuraki, Willie71 just to name a few and other makers / content providers trying to either upset / provoke them or prove he knows better than them.

Maybe if we report him constantly @Stacy E. Apelt - Bladesmith will finally get tired of him and deal with this, or maybe @Spark will have to be involved if that doesn't work. I'm willing to bet if you ask a few of the makers who don't renew their memberships anymore or participate in this area anymore for example @J. Doyle , newly registered trolls and most likely N Natlek will be mentioned as part of the reason.

https://www.bladeforums.com/threads/time-for-my-exit-adios-shop-talk.1634567/

https://www.bladeforums.com/threads/forging-vs-stock-removal-strengh.1631655/page-4#post-18669934

https://www.bladeforums.com/threads/call-for-charpy-toughness-samples.1548360/page-21

https://www.bladeforums.com/threads/commercial-heat-treat-furnace.1631340/#post-18640185

Sad that this even needed to be stated, or well restated again.

 

[Natlek]

You sir sound like a bad troll. Salt quench auto tempers for toughness.

I know what and way was used salt quench .I don t know quenching speed of salt .He get lower final hardness with salt ....Make sense now my post ?

I use Bohler's R100 steel which is equivalence for AISI52100 and I have tried those 1475F austenitizing several times and I got lower final hardness compare to 1550F.

 

[comet_sharp]

I know what and way was used salt quench .I don t know quenching speed of salt .He get lower final hardness with salt ....Make sense now my post ?

I use r100 as well. 1475° into parks yields 1 or 2 points higher for me than 1475°into McMaster Carr11 oil. Neither are as high a hardness as 1525 into parks or 1550 into mcmasterr, this 2 always quench 66 or higher. 1475° usually 2-4 points lower regardless of prior steel set up. Tested on surface ground coupons at 400 grit with a calibrated bench top rockwell tester.
I havent used njsb 52100 in 2 years so cannot say how it responds to HT.
I also austentize for 12-20 minutes with R100 based on thickness. I tend towards 15-20 though.
-Trey

 

[Natlek]

It should be pretty obvious that N Natlek is a troll, he always has been one so I doubt it will change. What isn't obvious is why he's been allowed to continue coming here for so long. People act like because he isn't totally fluent in English that something is lost in translation and his consistently arrogant and rude behavior is just part of his poor understanding of the situation. I would have to say that he understands what he's doing pretty well, when he consistently target's Larrin , @DevinT, @kuraki, Willie71 just to name a few and other makers / content providers trying to either upset / provoke them or prove he knows better than them.

Maybe if we report him constantly @Stacy E. Apelt - Bladesmith will finally get tired of him and deal with this, or maybe @Spark will have to be involved if that doesn't work. I'm willing to bet if you ask a few of the makers who don't renew their memberships anymore or participate in this area anymore for example @J. Doyle , newly registered trolls and most likely N Natlek will be mentioned as part of the reason.

https://www.bladeforums.com/threads/time-for-my-exit-adios-shop-talk.1634567/

https://www.bladeforums.com/threads/forging-vs-stock-removal-strengh.1631655/page-4#post-18669934


Sad that this even needed to be stated, or well restated again.

Lol...........keep trying

 

[Ocelot85]

Lol...........keep trying

Keep posting Keltan, I won't have to do anything. You're doing it all yourself.

 

[DeadboxHero]

I pay the full amount per article because every penny I put in goes towards more and better articles and useable data.

Larrin has some serious work ethic, he is able to write a new article every week. The man has a gift for writing.

This last wave of funding for instance went towards the metallography equipment needed for Larrrin to mount, polish and etch, 42 samples, some of the harder to get steels I personally donated and It was amazing to see everything lined up like that.


That kind of data is extremely valuable to the entire community. It helps elevate the community rather than the endless forum arguments between what people "believe" but never ever put in the time and money to prove or share any useable data.

We all should be helping out with this. I'm not working right now and I feel horrible for freeloading. A well written article is a ton of work and some of this cost money too. The fact that we can croud fund research into knife specific things is awesome. Its very likely that looking back from 10 years later we will see a trend of a large increase in performance of hand made knives do to freely available research.

 

[rodriguez7]

I pay the full amount per article because every penny I put in goes towards more and better articles and useable data.

Larrin has some serious work ethic, he is able to write a new article every week. The man has a gift for writing.

This last wave of funding for instance went towards the metallography equipment needed for Larrrin to mount, polish and etch, 42 samples, some of the harder to get steels I personally donated and It was amazing to see everything lined up like that.


That kind of data is extremely valuable to the entire community. It helps elevate the community rather than the endless forum arguments between what people "believe" but never ever put in the time and money to prove or share any useable data.

I didn’t know about that Patreon page. I just signed up! Guess I’ll be getting a knife steel nerds mug too!

 

[shqxk]

I use r100 as well. 1475° into parks yields 1 or 2 points higher for me than 1475°into McMaster Carr11 oil. Neither are as high a hardness as 1525 into parks or 1550 into mcmasterr, this 2 always quench 66 or higher. 1475° usually 2-4 points lower regardless of prior steel set up. Tested on surface ground coupons at 400 grit with a calibrated bench top rockwell tester.
I havent used njsb 52100 in 2 years so cannot say how it responds to HT.
I also austentize for 12-20 minutes with R100 based on thickness. I tend towards 15-20 though.
-Trey

This is pretty much similar to my experience.

I have heard from this forum that the 1475F austenitizing will yields highest hardness but after several attempt I know its not really true especially for R100 and Japanese's SUJ2 which you will always get significantly lower hardness like 2-4rc lower compare to 1540-1550F I normally use.

The quench speed of molten salt is faster than heated veg oil or medium speed oil but a little slower than fast oil. It can be use to harden W1 with auto hardened line effect tho.

The result I got have been duplicated by using both digital controlled electric kiln and digital controlled gas oven which has been calibrated regularly so I'm pretty sure about the conclusion.

 

[shqxk]

Have you made samples with this process for Larrin?

Lets see if I can make sample pieces and ship it to you since I dont have milling and surface grinding machine to finish up the piece to exact size. I also have some interesting steel which would be nice to test, it is Daido's GO5. This steel is close to 80crv2 in composition and its seems to tougher than 5155 with higher wear resistance than 52100 (noticeable harder to hand sanding).

 

[shqxk]

My favorite kind of heat treatment (although I’m no knifemaker, neither a Metallurgist!). That way, you can get some bainitic structure, if you want. And molten salt has the lowest temperature variations inside the pot, all places of the salt are (almost) exact same temperature.

Yes! if marquenching and soak it long enough we will get some bainite structure.

But I only quench and lets it equalize for 2 minute to avoid bainite as much as possible.

I have tried austempering in 450F salt for 4 hours and have it tested at 60hrc but it doesn't seems to hold an edge very well compare to regular heat treat.

 

[comet_sharp]

This is pretty much similar to my experience.

I have heard from this forum that the 1475F austenitizing will yields highest hardness but after several attempt I know its not really true especially for R100 and Japanese's SUJ2 which you will always get significantly lower hardness like 2-4rc lower compare to 1540-1550F I normally use.

The quench speed of molten salt is faster than heated veg oil or medium speed oil but a little slower than fast oil. It can be use to harden W1 with auto hardened line effect tho.

The result I got have been duplicated by using both digital controlled electric kiln and digital controlled gas oven which has been calibrated regularly so I'm pretty sure about the conclusion.

My experience to a T. I now use 1525 with parks50 or 1540 with medium oil. Any lower I noticed significant hardness loss
-Trey