grain size, 1095

K

Kurt Krueger

Well-Known Member
Below is a picture of a cross section from a blade I just heat treated. It's 1/16" 1095. Here's the process I followed:

Normalize for 10 minutes each at 1575, 1475, 1400, air cooling to black between each.
Austenized to 1475 and quenched in park's 50
Spheoridized at 1300 and allowed to cool in oven until it reached 135F (took ~ 6 hours to cool)

Austenized at 1475 for 15 minutes and quenched in park's 50.

My question is whether there is anything I can tell from the appearance of the fracture. The picture isn't perfect, but the break appears like a silver gray with no shiny crystal-like spots. In general, it looks like a broken file. I hope that's a good sign.

I can't say what the hardness is, I have access to a hardness tester, but can't get to it until tomorrow. In the mean time, I'm tempering the blades for two 2-hour tempers at 375. In theory, that should bring an ideally heat treated blade down to about 63.

Can anyone comment on the appearance in the photo?

Thanks

-Kurt
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I commented on the other forum as well, but just wanted to re-enforce it.....from what I can tell by the photo.....it does look good. It would be better if we had a close up shot, but I REALLY think you hit the nail on the head. If you look at it with the naked eye, and it looks velvety, like a broken file, you are THERE! Good job.
 
Thanks all. I have a supplier that probably has a microscope that's capable of taking pictures. I'll see if I can get a snapshot of my cross section.
 
I wasn't able to get better pictures of the fracture surface.

I was, however, able to get some hardness values,,, and I was a big disappointed. The as-quenched tip that I broke off tested at 63.5 (it got kind of hot when grinding away the decarb layer,, could it have tempered back the hardness? Maybe.), the blades themselves tested from 61 to 62.5. For the blades, there may be a bit of variability as a result of decarburization. I'm not sure how deep the decarb goes. I ground all surfaces down with a 120 grit belt, followed by a 220. There appeared to be some minor spots of "orange peel" appearance to the surface of the steel. I assume this is still part of the decarb layer.

While I may not have gotten as much from the steel as is possible, I suspect they'll still make decent knives. Not loosing any sleep over it.
 
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