Tripple quench, once and for all. Maybe

I must admit that I feel kind of silly now that I have backed up an looked at this thread. You folks realize that if we just admit that we are all cycling the steel to prepare it for the final heat treat, we have little left to disagree about, but when it is that we do the pre-treatments. Some call it normalizing, thermal cycling, others do it later and call it triple quenching.

I remember many years ago (I stress the many), I was still working with 5160 and I found that depending on the prior treatments I was getting unpredictable results. I had herd about the triple quenching, but I asked myself why I should wait until after the grinding to do the first two quenches? So I started to quench after the forging intermingled with normalizing. I just never put the cycling in the later hardening process, as I have said, I have my reason for this.
 
"Speaking of industry, people who really know how to take advantage of a good thing, why haven't all tool manufacturers abandoned the single quench for the obvious benefits to be gained by repeating it 2 more times? "

Added production cost in materials to heat the product? Added production time which would no only cost more labor but increase the possibility of injury to workers per item produced. Also added production time would increase the amount of time between cost of production of an item and delivery to the market. There are lots of possible reasons. Toolmaking and the custom knifemaker are really two different industries with two different standards and markets (even though they may use the same raw materials).

Personally, I do the triple normalizing (blades don't seem to warp so much when I do) but I only do 1 quench - only time I did the triple was when I made a rr spike tomahawk and triple quenched it in water. Seemed to help there, but that's not a good example. I am interested to see what Ed has up his sleeve for the Oregon show.

Kevin - good point about the cycling/normalizing/triple quench. Sometimes it helps to stand back and think a bit about what we're doing...lol.

Tim
 
While I can not speak for why the guys who know the most about steel and make tools with it, dont do 3 quenches... I can tell you that I have been unable to find anything writen by them to support the 3 quenchings....

It seems to me to be very believeable that a company does not do something due to the money it would take to do. But It just dont seem believeable that they dont even know about a value found in the 3-time quenchings.


Again, I have writen about a conversation I had with a welding inspector for Artic Cat Snowmobiles here this winter. I listen to this inspector talk about his job of insuring proper welds, and of training in the welders and of the many teachings seminars that he has been to in the industry.

He also spoke about the problems with stress within the steel, and how this is managed to ensure strong joints.

I was interested with his comments because so much of what he dealt with carries over into the problems we face in making a knife.

I questioned this Welding Inspector about the use of 3 or more heat-treatments and quenching and he informed me that there is nothing in any guidebook that he has ever come in contact with that would support my thinking that my knife steel benefited from extra quenching.

Now I could understand if he was told not to worry about triple heat treatments due to all the money it would cost the company to develop, but I just find it hard to believe that the triple quenching is beneficial and yet so many people in the steel business know nothing about it.

As far as I have learned in my own limited study of this and from the conversations with the very people who should know, I have seen that there is just no scientific support for my use of a triple quench.

There is tons of subjective proof, tons of stories about this or that knife that can really cut, but verifiable, repeatable evidence? I cannot find it
 
I personally couldn't care less about the underlying metallurgy in any heat treat formula. I want to know what works the very best for a given steel. I don't care at all why it works. If someone could disprove the triple quench theory, then I will gladly stop doing it, because it would be proven to be a waste of time. My shop testing, admittedly unscientific, yields results that indicate triple quenching improves the performance of my blades. My interest in the matter is solely one of improving the performance of my knives. If anyone can prove with testing that triple quenching doesn't help, I'll gladly change, but I'm not going to change because metallurgical theory says I should. I want the tests to confirm the theory.
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Todd well said.


Kevin you seem to believe that I am making this stuff up and spreading rash comments and half truths around. You also seemed to have missed the fact that I posted exactly what steps I took, how I did them and what steel I used and I'm not sure but It seems that you think I saw big foot. :eek:

You say that you are only intereste in what can be proven through science and that is ok with me. This world has been built by people of science. But Science has not always been the for runner. It has not always proven a theory before this theory was put to the test. It seems to me that some of the most important discoveries in the world through out times eternally past was at some point in time scoffed at by science. People scoffed at Leonardo DaVince's Ideas about flying machines and again at the Wright Brothers. They persecuted and threw Columbus in jail for his rash statements that the world was round and Sir Alexander Flemings Ideas from 1928 were thought uterly absurd until 1941 when science finally caught up to his thoughts and Discoverd that moldy bread could be made into a then wonder drug, that we all pretty much take for granted, called penicillin.

I am not claiming that people who are getting results that they are happy with using a single quench are doing things wrong. I am not saying that a triple quench is the perfect thing to do to every kind of steel out there or that there is such a thing as Sasquatch. I have laid out my practices for every one to see and try if they are of a mind to. I have not said that I have some undiscloseble practices that I cannot tell of but that they make phenominal knives when I can repeat them. I also invited suggestions as to what I did wrong in the single quench test I have done that would explain the inferior performance of these knives.

You want me to explain scientificly why the triple quench should work. I can't do this but I don't believe that you can prove that it does not. I am willing to agree that the triple quench may not and probably does not work in all cases and that imperceptible differences in technique will result in different results when cutting rope. But I will not believe that something that is minutely different in technique will make a difference of five times in cutting performance. I think that you are right in the fact that you can bend 1018 all day in a vice and prove nothing but that it will bend. But can you use your mystery techniques to harden it to 58 - 60 hrc and then bend it all day without having it break? comparing unhardenable mild steel to hardend L6 is no more fair than me asking the last question. Cutting rope and bending may not be the perfect test of a knifes ability but it will let a person compare two different methods used to harden grind, sharpen or whatever on the same steel or even compare two different steels if the same rope is used at the same time and place. They are also simple tests that any one can do. They are not tests that would mean much when done by two different people in different places at different times using different rope and steel.

So for the time being I say that we agree to disagree.


Bill
 
TimWieneke said:
Added production cost in materials to heat the product? Added production time which would no only cost more labor but increase the possibility of injury to workers per item produced. Also added production time would increase the amount of time between cost of production of an item and delivery to the market. There are lots of possible reasons. Toolmaking and the custom knifemaker are really two different industries with two different standards and markets (even though they may use the same raw materials).

Personally, I do the triple normalizing (blades don't seem to warp so much when I do) but I only do 1 quench - only time I did the triple was when I made a rr spike tomahawk and triple quenched it in water. Seemed to help there, but that's not a good example. I am interested to see what Ed has up his sleeve for the Oregon show.

Kevin - good point about the cycling/normalizing/triple quench. Sometimes it helps to stand back and think a bit about what we're doing...lol.

Tim
Click to expand...

I hear what you are saying Tim, but this is the second time that added cost has been given a plausible reason for the absence of such techniques in industry. Are we really thinking this through folks? Mr. Burke states 35 cuts versus 160 cuts in performance increase… does anybody really believe that industry would ignore a 350% increase in performance for any price? With those kind of results the standard operating procedure would be 3 times for everything and human sacrifice wouldn’t be too high a price for some to bury all the competition in the tool making market. For 20% I can believe manufacturing would cheap out and say it is not worth it. But for the kind of results that are often cited I know I would be willing to pay a higher price to buy one steel item that would out-perform like that.

If us bladesmiths can get that much abrasion resistance over normally heat-treated stock, we really need to get this thing scientifically studied and reap the benefits that such and advancement can give. I am serious about this. With those kinds of results, approaching science and industry with this could only bring fortune and glory. If I myself possessed the secret to such an improvement, I sure wouldn’t be making knives for a living.
 
Mr. Burke, please don’t do this, don’t pull this thread down by putting inflammatory things in my mouth that never came out of it.

”Kevin you seem to believe that I am making this stuff up and spreading rash comments and half truths around. You also seemed to have missed the fact that I posted exactly what steps I took, how I did them and what steel I used and I'm not sure but It seems that you think I saw big foot. ”

I never said or insinuated that you were making anything up or spreading half truths, I certainly never said that you personally saw big foot, and I must ask you to show how I did. In fact I used the Sasquatch analogy to drive home the point that people see things that they truly do believe in, yet science can have many other explanations and sometimes what we see with our own two eyes is not as it appears. I saw the exact steps that you posted and I can see where I would have drawn entirely different conclusions. Once again, apparent results and observed phenomenon are only subjective conclusions until the underlying causes are completely analyzed and understood.

“But Science has not always been the for runner.”

What has? It has been fairly common for me to encounter bladesmiths who try to use science to support their conclusions, but when they are faced with the fact that scientific principals do not support their ideas, they reject science as flawed. I have seen your exact argument many times before, the problem is it is not a preference type of thing. The laws of physics do not have an on/off switch for when they are convenient for our positions. We started out wholey embracing a scientific method to prove or disprove this thing. Now science is fading to the level of medieval mystics :confused: .

” It has not always proven a theory before this theory was put to the test. It seems to me that some of the most important discoveries in the world through out times eternally past was at some point in time scoffed at by science.”

I sincerely want to see this one put to the test. Is this one of the most important discoveries? Let’s find out. It has nothing to fear from science if it is sound and useful. Let’s have a proponent take it to a material science lab, or make a proposal to a CEO on how to get five times the performance out of a steel product. If it holds up, I will be the lonely fool next year this time and there will be some very wealthy people to laugh at me.

“People scoffed at Leonardo DaVince's Ideas about flying machines and again at the Wright Brothers. They persecuted and threw Columbus in jail for his rash statements that that the world was round.”

What about Galileo, don’t forget Galileo, he was really mistreated and imprisoned for his radical ideas. Da Vinci , Galileo and, I daresay, even Columbus and Orville and Wilbur, were the scientists of their time. It was the superstitious, unenlightened, medieval minded people of their time, not science, that scoffed at these men that used logic, reason, and disciplined methods of observation based on established principals, to achieve their goals. If quenching 3 times can approach the achievements of these men, then what are we waiting for?

"I have not said that I have some undiscloseble practices that I cannot tell of but that they make phenominal knives when I can repeat them…
But can you use your mystery techniques to harden it to 58 - 60 hrc and then bend it all day without having it break?"

These two lines would be most offensive, if you knew me, but since this is the first we have communicated, I must let them pass without any hard feelings. Anybody who knows me knows that I passionately DESPISE secrets and that all of my shop practices are an open book. I will tell you any part of my procedure without reservation. I have no undisclosed or mystery practices. What I refuse to tell people are some results I have gotten in testing the product of those practices. That’s right, I have been very pleasantly surprised with some of my performance tests and I refuse to boast of them! I feel I have a responsibility to verify those results completely before making statements about the performance of my blades, that I cannot explain. Even then, I will still let the customer decide. It is, after all, just steel, just well heat treated steel. If I tried to keep my techniques a secret, one trip to the library would blow me out of the water.

"You want me to explain scientificly why the triple quench should work. I can't do this but I don't believe that you can prove that it does not."

I don’t need to and I don’t wish to try. In fact I am here to say that I have no problem with your faith in, and use of, this method at all. If it is a great selling point for your knives, more power to you and God bless. I am just want to offer another viewpoint for those who may read this thread and hear the same elsewhere. You give your conclusions and results and I will give my points and information and we can let the people decide. That is only fair.

I am not here to attack or inflame, I just want to offer some other explanations.
Much of the triple quench thing has had an unchallenged platform for some time, if it is as good as you say my words can’t hurt it. But people deserve to hear all sides.
 
Sir Alexander Fleming "scoffed at by science" ? Absolutely not . The medical 'establishment' has always been reactionary. It's the all too common "I never heard of it therefore it doesn't exist" syndrome.They never tested his ideas scientifically ,they just rejected them.It was the lack of science that held back these people and their ideas."Science" has all too many people who should be scientific but are not , they are reactionary, and PC instead.......Cost factors in manufacturing involve wanting to get something for your dollar. If you tell me your procedure will give me an improvement in performance of 10% but costs 50% more , I'm not interested but reverse that and I'm very interested.
 
Kevin.

I wrote to a more experienced blade smith last year about his heat-treatments and he told me about this quenching during the forging that you listed as something you tried.

Can you tell me about this? I have been thinking about what use this would be? And if it did help at all, how it should be best done?

I forge John Deere Load shafts (5160) and it takes me about 3 days of work to get the steel flat enough and into the shape I need it to be in before I ever think about now Normalizing and annealing it. Along the way to that point, I will do my last heating of the session and then get the blade red hot, then just turn off the forge and allow the blade to cool inside it. Is there not a better chance of a crack to form if I suddenly plunged the hot blade into a bucket of oil during the forging process?

I actually did do a "Hot from the forge and into cold oil quench" on a few blades, but I had one crack, and another got weird spots along the sides from something so I gave it up.

Is there any advantage to a forging quench?
 
"I hear what you are saying Tim, but this is the second time that added cost has been given a plausible reason for the absence of such techniques in industry. Are we really thinking this through folks? Mr. Burke states 35 cuts versus 160 cuts in performance increase… does anybody really believe that industry would ignore a 350% increase in performance for any price?"

Again, we're comparing apples to oranges, but would a 300% increase in paid time and raw heating materials be worth a 350% increase in "performance" to a manufacturer? Maybe, maybe not - depends at what the market will bear in the increased sales price of this extra performance. To the custom knifemaker the answer to increased performance would be yes because it's a matter of individual reputation, but I can't say that this would be the case for a manufacturer who is in the business of producing parts intended to be worn out and replace.


"But for the kind of results that are often cited I know I would be willing to pay a higher price to buy one steel item that would out-perform like that." That is an issue in the knifemaking world we have to deal with - determining "standardized" results.

Tim
 
Can we flame off and get back to this comment by Kevin:

Kevin R. Cashen said:
I must admit that I feel kind of silly now that I have backed up an looked at this thread. You folks realize that if we just admit that we are all cycling the steel to prepare it for the final heat treat, we have little left to disagree about, but when it is that we do the pre-treatments. Some call it normalizing, thermal cycling, others do it later and call it triple quenching.

...
Click to expand...

Boy if that doesn't just say it all!

Here's another quote from Glyn Meyrick, Professor Emeritus and friends:

The microstructure of a steel depends upon its prior thermo-mechanical history. For example, a hot rolled plain carbon steel can consist of equiaxed ferrite grains and pearlite nodules. If the steel does not have the microstructure desired for its application or for the next process that is to be performed on it, then the icrostructure is changed by heat treating.
Click to expand...

Same basic point! The condition of the steel prior to any given step will effect the outcome of that step.

Look we all have to agree that the final quench is the final quench. During the third cycle you are raising the steel back to austentite. It ain't martensite at that point any more. So your final quench is what makes the martensite.

The difference is the steel structure BEFORE the infamous third cycle.

I don't want to put words in anyone's mouth, but ...

The process of creating austentite and then martensite is a very scientific known, studied process. When most of us use a term like triple quench we just throw it out there because it is a process WE perform. When the metallurgist heards that term he is thinking of the physical processes the STEEL performs. The non-metallurgist thinks that triple quenching has come kind of cummulative effect. "One quench is good, two makes even more, three makes as much good stuff as you can get." The metallurgist trys to explain that is it not cumulative, but rather the first two quenches are changing the structure prior to the final (or better yet the real) quench.

Re-read Kevin's quote. He is offering a hand of friendship, cooperation, and acknowledgement of the real results people are getting. Kevin has never (that I've read) questioned anybodies results.

------------------------------------
Can I just say the magic of the triple quench merely points out that the microstructure of the bladesmiths steel, prior to the first quench is not where it should be. (As mete points out, that is all very depending on the steel's composition and history. I'd like to go further in that, but not here.)

Now the question is simply how do you get steel in the best possible condition prior to the final heat/quench cycle?

If we keep harping on "You have to triple quench" we aren't progressing. Or worse yet, state all steels need a triple quench.

Maybe Kevin and Mete cannot only duplicate the effects of the first two quenches, but have a procedure that is superior in time, effort, or even results.

Steve
 
Just for fun, how about we drop the phrase triple-quench?

Would everybody be happy with:

"I preceed my hardening process with 2 rapid-cooling, normalization cycles."

Seriously, is that OK with everyone?

Steve
 
I can't help it, I'm going to keep going on this:

Let's call the optimum structure of the steel prior to the real/final hardening cycle: foo-cubic-goodness.

For alloy-1: the best is foo-cubic-goodness-1.
For alloy-2: the best is foo-cubic-goodness-2.

etc.


Now pretend I bought alloy-1 and it was hot rolled. It came to me in condition foo-cubic-goodness-1 already. And I used stock-removal and never changed its state. I performed one heat/quench cycle and got the best blade possible for alloy-1.

Now you bought alloy-1 and it was cold rolled. It was in state fum-cubic-brittle-1. You used stock removal, one cycle and the results were terrible. Then you tried the 'triple quench'. After the second quench your steel is now in condition: foo-cubic-goodness-1, you didn't know it but it did. This blade is way better than the first.

Now some third party, scientist buys some alloy-1 cold rolled. He sees the structure of the steel is not in foo-cubic-goodness-1. So he does some kinda process and achieves that state. Then does one heat treat cycle and gets optimum results - the same as mine and yours.

All three blades are now just as good. But you try and tell me my blade isn't top of the line based on your results.

---------------------------
Let's keep going. Party 4 buys alloy-2 and forges it. His forging is never very hot and when he is done the steel is in foo-cubic-goodness-2. He does a single quench cycle. Gets a great knife. Then he tries another with a triple quench, no real difference.

Party 5 buys alloy-2 and forges it. But gets the steel up to 2300 degrees and burns it. He tries single quench, triple, 14 normalization cycles, and an spheriod anneal. All his blades suck, because of the steel's history it will never achieve foo-cubic-goodness-2. It needs a re-melt.

Now pary 4 buys alloy-1 and forges it. But when he's done the steel isn't in foo-cubic-goodness-1. Because of the alloys it needs normalizing. He does a few normalizing cycles and achieves foo-cubic-goodness-1. Does that mean alloy-2 needs normalizing?

------------------------------------------------
Look for every steel there is probably a state of foo-cubic-goodness-x. As long as you get that state prior to hardening you're fine. Some steels get there easy, some hard, some get there while forging, some don't. The steel's history has a huge influence.

---------------------------------------

Am I making any sense?

Steve
 
When quenching into oil at say 120 deg F; are we really quenching at 120?

I use a digital thermometer to monitor quenchant temp, and note that

quenchant temp may rise from 6 to over 30 deg F, depending on quenchant

volume and blade size.

So...is the real quench temp 120deg F? or is it higher?

The latter seems more likely.

Russ
 
Sando , to add to your post I'll re ask my question since I didn't get an answer.Is L6 supplied in the spheroidized condition ? if so why was it done again , in fact done twice ? .......Russ ,the type of quenchant and it's characteristics are the most important, small differences in temperature won't make that much difference. In a past post I asked the question ,again unanswered, whether anyone had a circulating pump in his quench tank? Regardless of the quenchant you should always have a generous amount of quenchant so the temperature doesn't rise too much when quenching. When you plunge a 1500F piece of steel into the quenchant you will vaporize a layer of quenchant.The purpose of a circulating pump or agitating the knife is to remove that layer of vaporized quenchant. The knife should be quenched edge down or point down, never flat. The agitation should also be up and down or spine to edge never side to side.
 
Mete, Thanks.
My practice is pretty much as you suggested, except that my tanks
do not have circulating pumps. I rely on volume and agitation.

Russ
 
OK I re-read Mark's thread opener. Now I feel kind of silly too.

Mark you were right and said it simply. I, on the other, hand had to go on and on.

OK now I got the point.

Steve
 
rnandrews


I have asked some well know experts about the temperature of the quenching oil, and have always been told that anything in the 130- 135 degrees range will do fine for mineral oil.

It must be a bell-curve thing where you can get away with on both ends and still have a very good temperature to quench a blade in.

I know that I heat-treated 3 different blades one time, and one of the blades I had to do twice when I dropped it into the oil wrong. And when I was done I looked at the thermometer and it was reading about 170.

All that hot steel in the oil had raised the temperature 40 degrees in just a few moment, even in an un-heated shop with a room temperature of about 20 below zero.


The hot oil moves around the blade faster than the cold oil, and so the faster oil cools the blade faster and thats what we are aiming for in the quench.
 
DaQo'tah Forge said:
Kevin.
Is there any advantage to a forging quench?
Click to expand...

Yes, I think so DaQo'tah. I do this, not strictly speaking a hardening quench though. I always let the steel cool to a black heat before quenching. I walk out side and hold it in the tongs in the dark shadow of the shop (I always forge at night) until the red disappears and then quench. It is still hot enough to rile up the oil. This does several things. One, it helps contol over-heating and maintaining a localized heat, especially when working off the bar. Two, the burned in carbon from the oil helps minimize scale and helps maintain a fuel/carbon rich reducing atmosphere in the fire. Three, accomplishes a quick cool.normalizing grain reduction. I think Kevin is right, all this amounts to multiple grain reductions, no matter when it occurs, as long as it is prior to the final hardening quench. Yes, the scientific method and empirical observation will always trump hoo-doo and sympathetic magik, but intuition born of long experience and observation will get you there too.

Richard Mize
Fox Creek Forge
 
Mr Cashen or mete could you give me a walk thru for 4 different steels (1080, 1095, 5160, and L6) with temps and times to make in your opinions the best blade possible? what should i do with each steel when i first get it to get it ready?
 
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