How to Heat Treat 52100

Natlek said:
Charpy tests , theory and paper are only one side of the medal , have you ever made knife from 52100 steel with your recommended protocol and test it ? I know knife maker from Serbia who use 52100 steel and he make many, many tests on KNIFE /not on square piece of hardened steel/ with different HT protocol and he come to conclusion that 800 Celsius is best for 52100 of course with his normalization procedure /“thermal cycles”/ after he forge knife .He constantly get 66-67 HRC after quench .....................There was are plenty video clip on tube where he test his knife ......as proof .
You can make one knife with your protocol and repeat his tests and then compare result .............
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This is Larrin's DET protocol
It made the best 52100 knife so far.

66rc after tempering, very stable and cut longer than the other protocols I've done on rope.
I'm very happy with the Performance compared to other protocols I've used and tested.

Have you tested? Give it a try.



Cleaned up nice too.

 
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Natlek said:
Charpy tests , theory and paper are only one side of the medal , have you ever made knife from 52100 steel with your recommended protocol and test it ? I know knife maker from Serbia who use 52100 steel and he make many, many tests on KNIFE /not on square piece of hardened steel/ with different HT protocol and he come to conclusion that 800 Celsius is best for 52100 of course with his normalization procedure /“thermal cycles”/ after he forge knife .He constantly get 66-67 HRC after quench .....................There was are plenty video clip on tube where he test his knife ......as proof .
You can make one knife with your protocol and repeat his tests and then compare result .............
Click to expand...

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.

I also do 5 step thermal cycle before quenching and I got 59rc with 1475F and 61rc with 1550F after 400F tempering.

For now I would recommend

1650F 20 min air cool
1550F 30 min air cool
1550F 15min quench in oil (I use low 400F molten salt)
1200F 30 min air cool x 2
and 1550F 15min ---> quench to hand warm and then immediately to freezer for 15 min
400F temering x2

This will give 61rc with very fine grain structure and reasonable toughness.
 
DevinT said:
No one cares what you think.

Hoss
Click to expand...
Here we go.....................again :) You have no right to write about me , it is personal ,you know that ? I have my opinion on subject of this thread after I read that link from our member Larrin , and you have problem with that ? Come on...........hi is adult and he not need you to defend him !! And from what I wonder ?
And you think I care about what you think of me ?
 
Natlek said:
Here we go.....................again :) You have no right to write about me , it is personal ,you know that ? I have my opinion on subject of this thread after I read that link from our member Larrin , and you have problem with that ? Come on...........hi is adult and he not need you to defend him !! And from what I wonder ?
And you think I care about what you think of me ?
Click to expand...

Still don’t care.

Hoss
 
Natlek said:
Here we go.....................again :) You have no right to write about me , it is personal ,you know that ? I have my opinion on subject of this thread after I read that link from our member Larrin , and you have problem with that ? Come on...........hi is adult and he not need you to defend him !! And from what I wonder ?
And you think I care about what you think of me ?
Click to expand...

You have made only a handful of knives, mostly from recycled preheat treated steel. You don’t use and don’t heat treat 52100. You have done little or no heat treating and yet you are critical of the testing. Do your own testing and report your findings.

A friend of mine’s car died on a busy road in southern California, the guy in the car behind him kept honking thinking that it would help. My friend got out of his car and approached the irritated driver and invited him to go try to start the stalled car while he sat in his car honking.

Hoss
 
DevinT said:
You have made only a handful of knives, mostly from recycled preheat treated steel. You don’t use and don’t heat treat 52100. You have done little or no heat treating and yet you are critical of the testing. Do your own testing and report your findings.
Click to expand...
I said that it is enough ....but you don t stop .OK ...I use and have HT at least 10 knives from 52100 .I have done HT on maybe more then 50 knives in high carbon steel ...And I ask you what the hell have that with mu suggestion to Larrin to make more test before he declare that that HT protocol is best of the best ?
Now , if we follow your logic ............HOW many knives have HT and make Larrin ? none ? two none ? And that make him what ?
I m not subject of this topic and you should really stop with this nonsense !
 
Natlek said:
I
And I ask you what the hell have that with mu suggestion to Larrin to make more test before he declare that that HT protocol is best of the best ?
Click to expand...
A quote from the article you didn't read:
"With this recommended heat treatment I am not claiming that it is the absolute 100% best possible heat treatment."
 
Natlek said:
I said that it is enough ....but you don t stop .OK ...I use and have HT at least 10 knives from 52100 .I have done HT on maybe more then 50 knives in high carbon steel ...And I ask you what the hell have that with mu suggestion to Larrin to make more test before he declare that that HT protocol is best of the best ?
Now , if we follow your logic ............HOW many knives have HT and make Larrin ? none ? two none ? And that make him what ?
I m not subject of this topic and you should really stop with this nonsense !
Click to expand...

I have been making and heat treating knives for over 41 years. I made my own heat treating furnace when I was 16 years old ~forty years ago. I have on hand over 3 thousand pounds of 52100 and have made hundreds of knives out if it. Larrin grew up here next to the knife shop and has helped me make knives for most of his life.

You still lack enough experience to be able to contribute to this discussion. Your opinions are worthless. I don’t think you are smart enough to glean anything from the testing.

Me and Warren did the heat treating for this testing and other tests and have put in hundreds of hours while you criticize from your computer keyboard.

We don’t care how you make knives. Until you contribute something of value, I will be critical of you and your work.

Hoss
 
DevinT said:
I have been making and heat treating knives for over 41 years. I made my own heat treating furnace when I was 16 years old ~forty years ago. I have on hand over 3 thousand pounds of 52100 and have made hundreds of knives out if it.
Click to expand...
What HT protocol you use on that 3 000 pounds of 52100 ?
How smart I am is none of your business , please .
 
Larrin said:
A quote from the article you didn't read:
"With this recommended heat treatment I am not claiming that it is the absolute 100% best possible heat treatment."
Click to expand...
Yes I read that article and rest of them . What are you claiming then ? That there is maybe better HT protocol , that more tests are needed ?
 
I would like to thank Larrin, Warren and Devin for their extremely generous offering of their time and expertise. This information is invaluable to us and its FREE! This is very important to consider because access to scientific measurements such as these are rarely free. I am have a PhD (not metallurgy unfortunately) and I have read countless scientific journal articles. Generally, unless you are employed by a university, you have to pay for such information. Subscriptions to scientific journals are not cheap. It is much more expensive to actually pay for an expert to acquire such data. Just to give you an idea where I am coming from, I was an expert in electron microscopy and I specialized in the acquisition of quantitative elemental data. I billed out my time at $50 - $300 an hour. This gives you an idea how expensive professional measurements can be. I consider myself to be a novice at knifemaking and as such I have many questions. These articles have answered many of those questions. I especially appreciate the quantitative data and the hours that were spent in acquiring it. Thanks.
 
shqxk said:
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.

I also do 5 step thermal cycle before quenching and I got 59rc with 1475F and 61rc with 1550F after 400F tempering.

For now I would recommend

1650F 20 min air cool
1550F 30 min air cool
1550F 15min quench in oil (I use low 400F molten salt)
1200F 30 min air cool x 2
and 1550F 15min ---> quench to hand warm and then immediately to freezer for 15 min
400F temering x2

This will give 61rc with very fine grain structure and reasonable toughness.
Click to expand...
If you don t get at least 66 Rockwell after quench , something is wrong with your protocol .That s all I can say to you
 
Natlek said:
If you don t get at least 66 Rockwell after quench , something is wrong with your protocol .That s all I can say to you
Click to expand...

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.
 
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Natlek said:
Yes I read that article and rest of them . What are you claiming then ? That there is maybe better HT protocol , that more tests are needed ?
Click to expand...
More tests are always needed. That doesn’t mean waiting until infinite tests are completed to provide a recommendation. We still write textbooks even though science hasn’t answered every question.
 
Not quite free, some of us support this work through Patreon because we see how important it is.


anonymous76 said:
I would like to thank Larrin, Warren and Devin for their extremely generous offering of their time and expertise. This information is invaluable to us and its FREE! This is very important to consider because access to scientific measurements such as these are rarely free. I am have a PhD (not metallurgy unfortunately) and I have read countless scientific journal articles. Generally, unless you are employed by a university, you have to pay for such information. Subscriptions to scientific journals are not cheap. It is much more expensive to actually pay for an expert to acquire such data. Just to give you an idea where I am coming from, I was an expert in electron microscopy and I specialized in the acquisition of quantitative elemental data. I billed out my time at $50 - $300 an hour. This gives you an idea how expensive professional measurements can be. I consider myself to be a novice at knifemaking and as such I have many questions. These articles have answered many of those questions. I especially appreciate the quantitative data and the hours that were spent in acquiring it. Thanks.
Click to expand...
 
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anonymous76 said:
I would like to thank Larrin, Warren and Devin for their extremely generous offering of their time and expertise. This information is invaluable to us and its FREE! This is very important to consider because access to scientific measurements such as these are rarely free. I am have a PhD (not metallurgy unfortunately) and I have read countless scientific journal articles. Generally, unless you are employed by a university, you have to pay for such information. Subscriptions to scientific journals are not cheap. It is much more expensive to actually pay for an expert to acquire such data. Just to give you an idea where I am coming from, I was an expert in electron microscopy and I specialized in the acquisition of quantitative elemental data. I billed out my time at $50 - $300 an hour. This gives you an idea how expensive professional measurements can be. I consider myself to be a novice at knifemaking and as such I have many questions. These articles have answered many of those questions. I especially appreciate the quantitative data and the hours that were spent in acquiring it. Thanks.
Click to expand...

I have a friend who is in industrial steel manufacturing, and he was shocked he could access these articles for free. It’s an incredible resource.
 
Natlek said:
I said that it is enough ....but you don t stop .OK ...I use and have HT at least 10 knives from 52100 .I have done HT on maybe more then 50 knives in high carbon steel ...And I ask you what the hell have that with mu suggestion to Larrin to make more test before he declare that that HT protocol is best of the best ?
Now , if we follow your logic ............HOW many knives have HT and make Larrin ? none ? two none ? And that make him what ?
I m not subject of this topic and you should really stop with this nonsense !
Click to expand...
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.
 
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