lines or cracks after heat treat?

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DannyDiablo

Joined
Mar 18, 2008
Messages
176
So I just got a few knives back from HT and there are lines that look like cracks all through out the knife..(Picture what real dry earth looks like)..They don't appear to be cracks but they don't seem to grind out. Is this something I did wrong or something that went wrong during the heat treat..Is the knife destined for the scrap heap...??
 
Sure Brett...

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1095 is not the easiest to HT because there are a number of problems that can be very detrimental [ping !] .Read the stickies about high carbon steels and their HT. The heat treater may not be so knowledgeble either !
This is why we suggest other steels for beginners such as 1084 .Those cracks don't look like they penetrate much [otherise the blade would probably brack the blade completely .They may also have to do with decarb.
 
Oh they penetrate alright...The knife in the picture above started as this...
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I went to a full flat grind just to try and get rid of the lines..I had 4 of them ht'd and they all have it
 
I think someone tried to straighten a warpage after Ht by hitting them with a hammer, mallet, etc. Those are the kind of cracks you get when a blade has been subjected to force after it's completely hardened, but not yet tempered. Just my thought. I would certainly call tru-grit and tell them the problem. Those blades are unsellable.
 
That makes a lot of sense David, If you look at these pics the one side looks like a bullseye and on the underside its cracked directly under the bullseye. I'm going to contact them, I understand things go wrong during HT but I'm thinking if I lose 4 blades out of 4 they might have something to do with it!

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I sure as heck would be calling Trugrit for some answers. I cant believe they would send them back that way without some heads up??
 
It is junk now. Are you sure it is 1095. Ive seen that before on through hardening steel that was quenched in water during forging. not to harden but just to cool it a little. I also had it happen when I was forging 5160 and knocked the blade out of my tongs and i fell into my slack tub. I quickly grabebed it out of the water and put it back into the forge buttttttt!
 
Where did the material come from? and are you sure it was 1095?. The only time I have had something similar happen was with some cat spring. It spider webbed but not to that extreme. I think it might have been a problem in the smelt especially if you had 4 fail in this manner. If you have another piece try it again and see what happens. Heck if you send it to me I will HT it for free just to see if it happens again. This would help figure out were the problem lays at minimum.
 
The first thing I thought when i looked at the photo was a hammer blow. The dendritic nature of the cracks makes me think it radiated from the center of that circle. I have seen ( and caused them myself) such cracks done by cold forging a blade to try and straighten it, as well as forging at too low heat.

Put one in a vise and bend it. See what happens. If it bends without snapping any more than a regular blade would, they may make OK bench and personal use knives.



Important question:
When they came back from HT, did the cracks show, or did they show up after post HT grinding?
 
Hello Gentleman...I ordered the material from usknifemaker and it did say 1095 on the steel itself. Thank you Chuck I may take you up on that but I would have to give you something,And yes Stacy the cracks did show before I began grinding..I have pics of a couple of the blades I have not gotten to yet. The hidden tang had the tip crack off..

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I tried putting the one blade in a vice and bending it and it just snapped along the cracked sections...It didn't bend at all!!
 
WOW:eek: Those definitely do not look right. They look way over heated to me. Do you know if they used Turco or some other type of anti scale compound? That might explain the look of the surfaces but they still don't look right. The edges look severely degraded. If you still have some of the bar you used and decide you would like me to do a HT, please send me a blade and a piece of the bar to compare. All I ask is you cover postage. But I think just looking at these photo's there is something not right there.
 
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I bet the end looks like 100 miles of bad road. I can see the grain structure is HUGE. Yup Tai said it best.
 
It does look fried,... but also contaminated... one or the other, or both.
 
I've never seen anything so hideous! It does look like you ground the blade too thin pre-HT, which would cause the blade to bend during quench. That would be the reason to need straightening.

I'd most certainly call tru grit about it!
 
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