HT Repeats

S

Stevemo

Joined
Apr 28, 2018
Messages
11
Read a very old post from a member, an ABS Master Smith, that recommended running your heat treat 3 times. I have never read this advice before, but I respect the source and figured it was worth asking about...

thanks
 
Ed Fowler came up with that technique. There is no real metallurgical advantage of three quenches if you do a proper normalization/grain refinement before the quench.

There have been many threads and arguments about this, but it basically fell to those who like Ed and his methods, and the rest of us. I don't recall any non-Ed person who saw any benefit in triple quenching. You can probably tell which side of this topic I fall on.

You didn't link the old post you were talking about, so it may be by someone else, but I don't think Ed Fowler is an ABS Mastersmith.
 
Last edited:
I did not ask why. It was a post that was years old and I was not yet a member. I went looking for it and could not find it. The author was not Ed Fowler. I will look for it and include it.
 
I was just about to link Larrin's article. It seems there is some science that suggests quenching from a martensitic state is better. This falls in line with advice I was given by an ABS Mastersmith.
 
Multi quenching does has its own benefit due to you get the finer grain structure each time doing a quench. But at the risk of cracking/distortion. Hamon activity is a good evidence if this since the more you quench the lower of hadened line due to the finer geain lead to lower hardenability.
 
Isn't that info mainly related to High Speed Steels like M2?

I completely agree the grain refinement and other thermal procedures will yield a better blade, and that Martensite is a good place to be before the final quench. My biggest disagreement is from claims of greatly increased blade performance or grain size.

There appeared to be little reason to do it with standard carbon steels, and the claims of three times the edge life, ten times smaller grain, and greatly higher hardness for 52100 were purely bogus, IMHO.
 
Stacy E. Apelt - Bladesmith said:
Isn't that info mainly related to High Speed Steels like M2?
Click to expand...
The article shows the effect of prequenching on both D2 and M2, and in Grange's study on alloy steels he also found that a martensitic starting microstructure led to finer grain.
There appeared to be little reason to do it with standard carbon steels,
Click to expand...
It's funny to hear you say that because at times in the past one of the "advantages" of carbon steels touted is that they would respond to cycling treatments and that tool steels would not. The grain size of carbon steels can be more difficult to control because of the lack of pinning carbides at higher temperatures. Generally you have to work harder to have significant grain growth with high alloy steels.
and the claims of three times the edge life, ten times smaller grain, and greatly higher hardness for 52100 were purely bogus, IMHO.
Click to expand...
I agree that improvements in edge retention are unlikely to result from grain refinement.
 
You must log in or register to reply here.
Back
Top