Odd crack after quench

Metalhead0483

Metalhead0483

Joined
Jan 17, 2008
Messages
539
We've all had blades crack in the quench, but I'very never seen one like this. Anyone else seen a lengthwise crack like this? Struck me as odd...

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Happens from time to time. It is c alled a lateral crack. It may come from st-hearing stresses in the quench, or from a pre-existing problem in the bar of steel.
 
Stacy E. Apelt - Bladesmith said:
Happens from time to time. It is c alled a lateral crack. It may come from st-hearing stresses in the quench, or from a pre-existing problem in the bar of steel.
Click to expand...

This is the first knife I made from those fencing foils I posted about a couple of months ago. Not sure if you remember. It's been an interesting progression to date. I thought I had the heat treat figured out based on my testing, but I guess I have some work still to do...
 
Just a thought. You said it was forged from a fencing foil. The foils of today have small channels running the length of the blade for a wire that is for electric scoring. It is possible that unless you ground that channel out before forging you actually forged the crack in from that channel. You basically forged in a stress riser. A possibility.
Brion
 
Brion, I was thinking along the same lines. I recently learned the hard way about forging in a crack from an existing groove.
 
Most likely it was made of 9260 from Europe .Similar to 5160 in use . Back in the 1960s and 70s the steel was very dirty [ inclusions ] .Could have been a problem with a long stringer of inclusions though I've never seen that in blades. 9260 is a high silicon steel. If you mean a surface fold that's possible.
 
mete said:
Most likely it was made of 9260 from Europe .Similar to 5160 in use . Back in the 1960s and 70s the steel was very dirty [ inclusions ] .Could have been a problem with a long stringer of inclusions though I've never seen that in blades. 9260 is a high silicon steel. If you mean a surface fold that's possible.
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Hmmm, hadn't considered 9260. The foils are old square cross-sectioned ones made in France and Italy, although I can't trace a specific date.

Whatever it is, it doesn't harden in oil, I've had to use a water quench to harden it up. I'll do some research on 9260...
 
On a side note...
It may just be the pic but those grind marks look awfully deep and run right off the edge. I would try to avoid that, if possible.
 
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