Strange Etch Effect...What Gives

[Wes Detrick 487]

To add to what Jake and Gabe said, get some stainless foil to wrap the blade in when you are thermal cycling.  It will protect it from the oxidizing environment.  Only take it out of the foil when you are going to clay it up for the quenching heat.

[Charlie Meek 54]

You know I didn't really think about that but the file was moving metal so I would think any decarb would only be so thick though, right?

I'm going to repost this in the metallurgy and heat treating section.  I hate to chew space here when people probbaly have some good succeses to share. I think the issue is my thermal cycling. It's probably more appriate to 5160 than 1095 anyhow. Its all part of the journey i suppose haha. 

[jake cleland 437]

It's easy to check - just file the edge of your cracked blade until you hit hardened steel. You're overthinking this - struggling to harden a simple steel in oil is a good thing - leaving large grain size to increase hardenability is not. 

[JJ Simon 123]

Well, it hardened in the water or it wouldn't have cracked while going through transformation.
I'd suggest breaking it the rest of the way and looking at your grain.

[Charlie Meek 54]

Yup it was decarb. Lessons learned. Super grain though. Very tight and gray, no sugar or sparkles. 

Edited August 2, 2017 by Charlie Meek

[Gabriel James 90]

glad u learned ur lesson, I still cant figure out why my 55 gallon kiln wont stabilize top and bottom temps now. cant get them closer than 100 degrees apart. A few months ago they were 5-10 degrees apart. About to pull my hair out