Can JTknives feel a bad HT when a knife is quenched?

Can JTknives feel the difference in energy vibes between a good and a bad quench?

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Mecha

Mecha

Titanium Bladesmith
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In a recent thread started by JTknives, he mentioned that he can feel it when he quenches a blade and something is wrong with the heat treatment. The vibration or energy during phase transition feels different, he says.

https://bladeforums.com/threads/more-1084-weirdness.1693606/

Now, some folks would dismiss this as part of the forged grain flow / samurai sword whisperer / unicorn-based quenchant / point the blade true north / harmonic sword resonance sort of thing that's often dismissed as "unscientific" and thus impossible.

I, for one, believe JT can indeed feel differences in the vibrations/energy of what's happening when he quenches a blade that he is holding, but then again, I'm a grain flow believer and also believe in tin foil hats, and refuse to use a smart phone.

What say ye? Does JT also wear a tinfoil hat? Or is he simply noticing subtle differences as he quenches blade after blade? o_O Let us know in the poll!
 
What are you proposing that he feels that counts as "bad"? Warping? Cracking? How long it takes before martensite starts forming? If it transforms to soft pearlite instead? Some of these are easier to tell than others.
 
Larrin said:
What are you proposing that he feels that counts as "bad"? Warping? Cracking? How long it takes before martensite starts forming? If it transforms to soft pearlite instead? Some of these are easier to tell than others.
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I'm thinking that among the ones that turned out poorly (didn't form martensite), there was a similarity in the way it felt that differed from the majority of them that were good.
 
Larrin said:
What are you proposing that he feels that counts as "bad"? Warping? Cracking? How long it takes before martensite starts forming? If it transforms to soft pearlite instead? Some of these are easier to tell than others.
Click to expand...

Very simply put, the ones he ultimately defined as "bad" felt similarly different from the ones he defined as "good."
 
I’ve heard the “Tink” of a crack/warp myself, I will reference this with being a Stock Removal maker for most of my knife crafting career .. JT may feel the diff when quenching in Parks 50?? Many use his HT services so he’s got quite the following. Go JT!:thumbsup:
 
Most knife steels grow when quenched, especially carbon steels. They shrink some when tempered but not enough to overcome the growth. I think the Japanese have a name it, it’s what makes the curve in a samurai sword.
You can feel that movement when you quench.
Hoss
 
It's called Sori if I remember well. A katana will develop positive sori when quenched in water and negative sori when quenched in oil.
 
DevinT said:
Most knife steels grow when quenched, especially carbon steels. They shrink some when tempered but not enough to overcome the growth. I think the Japanese have a name it, it’s what makes the curve in a samurai sword.
You can feel that movement when you quench.
Hoss
Click to expand...

I believe this is the reason from when steel is heated up there are thermal expansion, and once it was quenched in the water, the thinner section of the blade cool are cooled down first, thermal contraction in that area pull the blade bending downward.

Once the thicker part (which always been clay coated as traditional Japanese technique) the blade becomes straight...

and once the temperature is cool down enough to hit the martensite start temp. The thinner area which successfully quench passed the pearlite nose convert into martensite. The thicker area under the clay remain pearlite. Since martensite has higher volume its push the blade to bend upward thus sori.

The question I don't understand is why the oil has negative effect on the sori?

 
Joel Mercier said:
Probably because the steel is extremely shallow hardening and less martensite forms. Just a guess...
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I doubt that will be the case because from my experience, quenching in oil or water yields very similar hamon proportion.

And the knife blade is pretty thin, I have had HRC tested that they will harden all the way thru without clay coat quenching in oil (W1 tool steel)

Here is the blade I just quenched several days ago. At first attemp I quenched in water, the blade remain straight but the hamon wasn't good enough. The second attempt I didn't want to take a risk so I quenched in fast oil and the blade bent downward.

73274206_2493647400689357_3396429119422988288_n.jpg
 
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No no, sorry for the misunderstanding. I was referring to the tamahagane steel of a katana, not 1084. Tamahagane can have extremely low amount of manganese and water can be the only way to get decent hardness.
 
Actually you're right about "Katana will develop positive sori when quenched in water and negative sori when quenched in oil"

I have seen this happened to almost every simple carbon not just tamahagane. From W2 to 1050. I still can't figured out why quenching in oil develop reverse sori tho..
 
There is a definite "resonance" that can be felt through the tongs. I give this one a plausible. I'd suppose even a rank amateur like myself could feel the difference between different materials or maybe significantly different profiles.

Side note: You guys that voted against the turtles got issues. Now I have to approach everything you say with suspicion.
 
tkroenlein said:
There is a definite "resonance" that can be felt through the tongs. I give this one a plausible. I'd suppose even a rank amateur like myself could feel the difference between different materials or maybe significantly different profiles.

Side note: You guys that voted against the turtles got issues. Now I have to approach everything you say with suspicion.
Click to expand...

Threads like this result in everyone viewing everyone else with suspicion.

And just for perspective's sake, here's me wearing my ritualistic heat treatment garb in preparation to conduct a heat treatment ceremony:

vCmMgMv.jpg
 
The carbon steels that I have quenched that failed to harden feel different while quenching. I don’t mean I'm using some weird Jedi quenching force. The vibration of the tongs is different. As the steel quenches you can feel the bubbles and vapor jacket vibrating the steel. On a good carbon steel blade it’s calm at first and quickly rises to a peak with a sudden drop off of all vibration. On the crap steel is called for a lot longer and it slowly builds but very mild. Then it drops off and you think it’s done but if you wait just a few more seconds you get a second vibration as it cools all the way. It’s weird but very noticeable to me. I would wadger a bet that I could tell them apart blindfolded. Might be a fun test to try actually.
 
Mecha said:
Very simply put, the ones he ultimately defined as "bad" felt similarly different from the ones he defined as "good."
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X2. This is experience and “feel” ... with time and experiment it might be possible to translate into avspecific materials/scientific statement .. but keep n mind that there is a LONG history in many disciplines of craft preceding science (and this is me, the ultimate theory weinie, saying this..... )
 
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