Can triple quench secrets to be revealed? Yes, for sure sometime.
Am I revealing the secrets now? I do not know, just giving a nice try.
To be understood:
(1) I am not a native speaker of English, sorry about language mistakes.
(2) I am not a metallurgist, just have read some books for fun.
(3) I am only a hobby smith, making a "brain gym".
The triple quench mystery is especially interesting (for brain gym), because it is not only one unsolved problem ??? (I mean, reasons why it works) but also seems to have a logical contradiction.
On the material world there are not, however, such things as logical contradictions (I am not talking about the world of ghosts or spirits)!
(1) Ed Fowler's tests show triple quench works, and is reliable.
(2) Metallurgists say it can't work, steel has no memory and if we quench many times it can't be better. And they have their own proofs.
Here we have seemingly a logical contradiction. So, we just have to find out why really the knife is better when quenched 3 times even the hardening (changing austenite to martensite) can't to be explained to do anyting like that.
"Seemingly" is the key word.
I have worked one lifetime with computers and did learn that always when I am saying "this is impossible, can't work like this", there is a perfectly clear explanation just to be found.
So, there is some odd factor x, which happens during the triple quench process (not to change austenite to martensite). Which is it?
Now, to the factor x:
Let start with fashionable "super steels". (I am a hobby smith and do the work for the old tradition. I am not very interested on fancy alloys, which demand some fancy ovens and so on.) However, we can get the matter in the question more easy to understand with an example.
Mill specs about fancy steel x tell that you must keep the temperature y (high) for z minits (very many) before quenching. Nobody says: quench immediately when temperture is y.
Now, we can explain why we must to keep long time the heat. Many fancy carbides as Vanadium carbide are very reluctant to let out carbon as needed. They need lot of time and heat.
Unfortunately also ferrite carbides (carbon steel and low allow steels) need time (few minits) to let out some carbon as needed. (A low carbon steel is the most critical) So, basically the carbon steels are similar to fancy new steels, the keeping time exists, but it is much shorter.
A short (for carbon steel) proper keeping time do not enlarge the crystalline structure!
More error prone thing with carbon steel is to overheat it. Smiths are for this reason advised to quench "immediately". In practice a beginner smith always needs some extra minits to get long blade evenly heated and is satisfied the color all the way, and gets enough carbon out by accident.
Now, if we are skillful enough to heat optimally and really quench immediately we need 3 times to quench (and to heat for carbides) to provide the needed "carbon let out time" for optimal result (4 or 5 times even better ?). (Between the quenches the carbon do not re- enter into carbides.)
One more fact on favor my theory: Ed Fowler says that the steel seems more soft to sharpen after 3 quenches.
The hard ferrite carbides disappearing! Wear resistant carbides are also making knife more difficult to shapen (Cr-carbide HV 1600, V-carbide HV 2800 (HRC 85!))
If somebody want to test this (A joke, nobody will!), the difficulty is not to overheat because overheating is even more critical thing.
So, triple quenching protects from overheating and works, on the other hand it is cubersome.
pig from Finland
Am I revealing the secrets now? I do not know, just giving a nice try.
To be understood:
(1) I am not a native speaker of English, sorry about language mistakes.
(2) I am not a metallurgist, just have read some books for fun.
(3) I am only a hobby smith, making a "brain gym".
The triple quench mystery is especially interesting (for brain gym), because it is not only one unsolved problem ??? (I mean, reasons why it works) but also seems to have a logical contradiction.
On the material world there are not, however, such things as logical contradictions (I am not talking about the world of ghosts or spirits)!
(1) Ed Fowler's tests show triple quench works, and is reliable.
(2) Metallurgists say it can't work, steel has no memory and if we quench many times it can't be better. And they have their own proofs.
Here we have seemingly a logical contradiction. So, we just have to find out why really the knife is better when quenched 3 times even the hardening (changing austenite to martensite) can't to be explained to do anyting like that.
"Seemingly" is the key word.
I have worked one lifetime with computers and did learn that always when I am saying "this is impossible, can't work like this", there is a perfectly clear explanation just to be found.
So, there is some odd factor x, which happens during the triple quench process (not to change austenite to martensite). Which is it?
Now, to the factor x:
Let start with fashionable "super steels". (I am a hobby smith and do the work for the old tradition. I am not very interested on fancy alloys, which demand some fancy ovens and so on.) However, we can get the matter in the question more easy to understand with an example.
Mill specs about fancy steel x tell that you must keep the temperature y (high) for z minits (very many) before quenching. Nobody says: quench immediately when temperture is y.
Now, we can explain why we must to keep long time the heat. Many fancy carbides as Vanadium carbide are very reluctant to let out carbon as needed. They need lot of time and heat.
Unfortunately also ferrite carbides (carbon steel and low allow steels) need time (few minits) to let out some carbon as needed. (A low carbon steel is the most critical) So, basically the carbon steels are similar to fancy new steels, the keeping time exists, but it is much shorter.
A short (for carbon steel) proper keeping time do not enlarge the crystalline structure!
More error prone thing with carbon steel is to overheat it. Smiths are for this reason advised to quench "immediately". In practice a beginner smith always needs some extra minits to get long blade evenly heated and is satisfied the color all the way, and gets enough carbon out by accident.
Now, if we are skillful enough to heat optimally and really quench immediately we need 3 times to quench (and to heat for carbides) to provide the needed "carbon let out time" for optimal result (4 or 5 times even better ?). (Between the quenches the carbon do not re- enter into carbides.)
One more fact on favor my theory: Ed Fowler says that the steel seems more soft to sharpen after 3 quenches.
The hard ferrite carbides disappearing! Wear resistant carbides are also making knife more difficult to shapen (Cr-carbide HV 1600, V-carbide HV 2800 (HRC 85!))
If somebody want to test this (A joke, nobody will!), the difficulty is not to overheat because overheating is even more critical thing.
So, triple quenching protects from overheating and works, on the other hand it is cubersome.
pig from Finland
