Another O1 Question

Grain in 01 can be refined only so far before reaching the point of dimishing return. If you follow what Kevin, and AcridSaint said, you will be pretty much at that point, but if you insist on going further, have at it. Two, very savy metallurgists, have given you their opinions, based on many years of study, experimentation, testing, and practical application. I would have to believe that, were there any "significant" improvement in 01 from multiple quenches, they would know, and say so. If you doubt the merit of their opinions, then perhaps you should do your own testing and analysis of the processes. There is nothing wrong in doing that, if you have the time, equipment, and dedication to do it in a proper scientific manner, in which the results can be seen and proven, and consistently repeated, and not be clouded in a haze of smoke, or buried in BS.
 
LRB said:
Grain in 01 can be refined only so far before reaching the point of dimishing return. If you follow what Kevin, and AcridSaint said, you will be pretty much at that point, but if you insist on going further, have at it. Two, very savy metallurgists, have given you their opinions, based on many years of study, experimentation, testing, and practical application. I would have to believe that, were there any "significant" improvement in 01 from multiple quenches, they would know, and say so. If you doubt the merit of their opinions, then perhaps you should do your own testing and analysis of the processes. There is nothing wrong in doing that, if you have the time, equipment, and dedication to do it in a proper scientific manner, in which the results can be seen and proven, and consistently repeated, and not be clouded in a haze of smoke, or buried in BS.
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Show me the study that says that multiple quenches don't have a significant reduction in grain size, even after proper normalizing and annealing, then I'll reconsider. So far I've seen some feel good phrases about doing it right the first time and some aversion to bandwagons. If Kevin has done the test, then by all means, please share. Based on new information I can make new decisions.

The Verhoeven book talks briefly about the benefits of multiple quenching. Also, there were a couple studies about multiple quenching for air hardening steels, you can see one of the charts in the Heat Treater's Guide under D2, and some more information in the book "Tool Steels". With air hardening grades doing a multiple quench all at full austenitizing temperature has no effect on grain size or is detrimental, the initial quenches must be done from lower temperatures, for D2 it was 1600-1800F, and M2 was 1600-1900F. Why exactly that happens when you go too high it doesn't really say, but it probably involves the carbides dissolving and no longer pinning the boundaries, so the main thing is to get the temperature high enough to get full austenite without dissolving a lot of carbide.
 
The whole triple quench method was brought about by .....

First quench , blade warps to the left.
Second quench. blade warps to the right.

Third quench is because quench 1 and 2 resulted in warps :D

That and Ed Fowler has glorified the multiple quench = super high performance mantra :D
Just kidding Ed.

Merry Christmas Everyone.
 
Mark Williams said:
The whole triple quench method was brought about by .....

First quench , blade warps to the left.
Second quench. blade warps to the right.

Third quench is because quench 1 and 2 resulted in warps :D

That and Ed Fowler has glorified the multiple quench = super high performance mantra :D
Just kidding Ed.

Merry Christmas Everyone.
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As true or un-true as your statement is, it doesn't change what the process actually does.
 
mete said:
O-1 contains .20 V [Carpenter's version for example] which is there for grain refinement ! So multiple quenches are really a moot point.
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How much more do you need.



Heck , you can refine the grain to the point to where you cant quench it fast enough to harden, but should you?
 
I've single quenched hundreds of O1 blades, all different sizes, tested some to extreme measures and feel single quenching works fine. If multiple quenching helps, it probably doesn't show enough to really matter to me. I feel the same way about cryo treatments. If people want to spend the extra $$ on cryo treating so be it. I'll keep the extra cash in my pocket. :)
Scott
 
Gossman Knives said:
I've single quenched hundreds of O1 blades, all different sizes, tested some to extreme measures and feel single quenching is works fine. If multiple quenching helps, it probably doesn't show enough to really matter to me. I feel the same way about cryo treatments. If people want to spend the extra $$ on cryo treating so be it. I'll keep the extra cash in my pocket. :)
Scott
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Merry Christmas, Scott.:)
- Mitch
 
Larrin - I know your posts from knet and here and I know you've got a good deal of heat treating knowledge, so I'm not going to try to go head to head with you about whether or not the multiple quenches refine grain structure of O1. I just don't have the experience or book knowledge.

I do stand by my assertion that there is no great mystery to heat treating O1 or most other steels out there. Even if multiple quenching, O1 has a simple set of rules to "get it right", I think everyone should be able to agree on that. I do almost all of my heat treating in an oven and still only quench once. I have better control than many of the guys asking questions on here, but I also know that I have the ability to screw up my knife every time I put it in the oven.

I want to make sure we're both on the same page here, I am not denying that multiple quenches may be beneficial, in controlled heat treating situations. However, even in those controlled situations, I don't believe that the majority of makers or customers will find the difference staggering or in any way life changing. I do believe, however, that the maker is three times more likely to have some sort of mistake on his/her knife (if triple quenching).

Although I do want everyone making the best knives we reasonably can, I don't believe that hours upon hours at the oven or forge is the best way to improve my knives and is surely not the best way to improve a brand new makers' knives. Once I've got my finish perfected, my grinds immaculate and my fit so tight you'd think my knives were integrals, then maybe I'll start mucking around with getting every bit of extra performance out of the steel.

Now, after all that lengthy posting, I should also disclaim that I don't care to use O1. I like stainless steels and 10 series carbon steels. Namely 1084 and 1080 - both of which don't seem care about all of this hooey nearly as much as the more complicated alloy steels.
 
I hope you makers are not guessing .You should be testing your procedures by making sample with various steels and HT. Then notch the samples with a Dremel cut off wheel and break the sample .A simple and effective way to compare and see for yourself what grain size you have.
 
Larrin said:
... So far I've seen some feel good phrases about doing it right the first time and some aversion to bandwagons...
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Larrin you got these because - 1. This topic has been so beat to death that it really can't go any farther with positive results. 2. It is Christmas, and I wanted to leave things on a positive note, I thought I could take one day off this year of being a lightening rod for challenging the dogma of the bladesmithing zealots. I wanted to leave you with something "feel good" instead of starting yet another pissing match, your gratitude is somewhat underwhelming.
 
Is a proper soak & single quench 'good enough', meaning a multiple quench would provide only marginal refinement, or is a single quench 'as good as it gets', meaning additional quenches does nothing to refine the grain size?
 
Kevin R. Cashen said:
Larrin you got these because - 1. This topic has been so beat to death that it really can't go any farther with positive results. 2. It is Christmas, and I wanted to leave things on a positive note, I thought I could take one day off this year of being a lightening rod for challenging the dogma of the bladesmithing zealots. I wanted to leave you with something "feel good" instead of starting yet another pissing match, your gratitude is somewhat underwhelming.
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I didn't know this was a pissing match, I'm just trying to start a discussion. I've seen pages and pages on this topic of which nothing is discussed, it is a giant waste of time to read any of those threads.

If you're getting angry at my posts, then maybe I should aplogize; however, all I want is some numbers, a study, personal experience, anything. If you have looked under a microscope at multiple quenched steel vs. your single quenched steel, I'd like to hear about it.
 
Larrin said:
I didn't know this was a pissing match, I'm just trying to start a discussion. I've seen pages and pages on this topic of which nothing is discussed, it is a giant waste of time to read any of those threads.

If you're getting angry at my posts, then maybe I should aplogize; however, all I want is some numbers, a study, personal experience, anything. If you have looked under a microscope at multiple quenched steel vs. your single quenched steel, I'd like to hear about it.
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Larrin, you have your own microscopes, why do you need mine?

There is no pissing match here, and I wanted to avoid any from arising, I am angry because when I extend a friendly hand I am not used to having it slapped away with belittling remarks.

Too many of the makers going orgasmic over so many creative heat treating methods have about as much control over their testing process and the ability to analyze the results as a train wreck. They will often be the first to say that it is not important to know how or why things happen as long as they get the results they are looking for, which amounts to only so much belief and wishful thinking, and whole lot of biased interpretation of the results. Hard numbers are overkill against this.

New makers asking for information to get started need a solid listing of proven basics before being given eclectic advice on how to make unobtanium. For example, fast thermal cycling can indeed result in recrystallization of smaller grains, but perhaps it would be a good thing for somebody to figure out how to nail one quench with as little problems as possible before messing with repeating it again and again in hopes of getting astm grain size 14 instead of astm 9, when they should be very happy to be above 6 or 7 with the tools they have. We all have our own definition of what should be the most desirable qualities in a knife. One can fart around with quenching until the sole goal is prove how small they can make a grain, but other than this what is the point?

I have a saying for people who start spouting opposing politics or religion to me in my personal life- "Are you trying to convert me or offend me? Because it will only be one of the two." Triple quenching has many of the attributes of a religious or political movement. I don't bother much with these discussions because I can only hope to convert or offend and for true believers offending is about all I can manage.

I only post in these threads because folks new to heat treating deserve to know there are other views from the triple quench mantra, any deeper discussion is a waste of my time.
 
I apologize for my argumentative nature in this thread. Thank you for your contribution to the subject. I agree that knifemakers should learn to make a proper single quenched knife before delving into whether a multiple quench yields a benefit.

I don't have any microscopes. I'm at a University now that I may be able to use them. I have been speaking to a professor about a series of tests on stainless steels and multiple quenching. If there is already information I am missing I would like to see it first though.
 
Larrin said:
I apologize for my argumentative nature in this thread. Thank you for your contribution to the subject. I agree that knifemakers should learn to make a proper single quenched knife before delving into whether a multiple quench yields a benefit.

I don't have any microscopes. I'm at a University now that I may be able to use them. I have been speaking to a professor about a series of tests on stainless steels and multiple quenching. If there is already information I am missing I would like to see it first though.
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I apologize for the assumption about microscopes, I thought I remembered discussing your purchase or the intended purchase of a scope, I assumed you were now doing your own microscopy. Also don't get me wrong, I hope I covered it in my last post that you are correct that fast cycling will indeed reduce grain size, more efficiently, in my opinion than many forging operations. I have always agreed with that, I just have a difference of opinion about what part of the process those refining cycles should be brought into play. Grain refinement is a given and the very basics when discussing cycling treatments of any kind.

This is a lot like the cryo and retained austenite thing. The claims get so overblown about so many properties that reasonable people have to have doubts and question it. The defensive answer to this is a "have you quit beating your wife" kind of question- "Are you saying cryo doesn't work?"
Which is a setup, since cryo absolutely does work- for converting retained austenite. However this is so elementary that we aren't really thinking of this when we are questioning the bigger issues.

Fact-repeated fast cycling results in finer grain. Opinion/speculation- this will make the utlimate blade, and the hardening step of heat treatment is the only place to do it.

I get confused sometimes with what I want in these discussions. If I see a juicy topic my first reaction is to say "Great an opportunity for a heavy discussion and debate, what I nice Christmas present!", but then reality sets in and I think of how much fun it will be spending my Christmas arguing or raining on somebody's parade and I realize that we can take a break from being iconoclasts for at least one or two days a year. There will be 363 other days this year to debate the small stuff, in the meantime finding positive points is more in the spirit of the season.

Your questions are good Larrin, and better yet you are not wrong, I would just like to go back and make the sentiments of merry Christmas more unconditional.
 
I think there was something before about not going past 3 cycles on either quenching or normalizing because the grain wouldn't refine much more past that. What kind of basic assumptions would that rely on, like prior cycling/condition of the steel, precision in temperature control, cooling rates, etc.?

Rudolph.jpg
 
The debates continue and always will. All a maker has to do is make several similar blades out of the same billet of steel, try various methods and test the knives in his shop using his equipment, doing what he wants the knives to do. The more well thought out the performance experients the more obvious will be the results.

Science has never been a substitute for knowledge.
 
If you're using an oven to heat treat then you might be able to achieve some consistent results to test, but if you're using a forge or a torch, each of your similar blades will have had a different heat treatment. You should have only one variable, like quenchant, soak time, etc.

If we're heat treating 6 blades with a torch by eye, dipping them in the same bucket of oil that's getting hotter each time and just going by a wall clock to measure "a little while" after magnetic, we're not going to get any useful results.
 
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