Mixed Up

[pjelect]

I ground out a fixed blade 4 months ago but never finished it. Today I decided to finish it and heat treat it but forgot to mark the steel type. I know for a fact that it is either D-2 or ATS-34. If I heat treat it as ATS-34 I can check the results with my hardness tester. If it is instead D-2 I should get a lower hardness reading, right? Or can I get about the same hardness on D-2 at the lower heat treat tempuratures of ATS-34? How do both of these steels respond to a second heat treatment if I'm less than satisfied with the outcome of the first? I also thought of polishing it out now to see if get that infamous "orange peel" I always get with D-2 but I don't know if I would get it in an unheatreated state. Any suggetions? Thanx, Pat

[mete]

You could heat treat both steels the same, at 1900F. Not optimal for D2 and would probably get more retained austenite but a dry ice treatment would help [both actually] So harden from 1900F, oil or plate quench, snap temper 300-350F 2 hours, dry ice for 8 hours, temper 400-500F twice ,2 hours each. Give it a try.

[pjelect]

Thanks, Mete, I'll give it a try. Pat

[Don Robinson]

Good solution, Mete.

[TexasJack]

Another suggestion: If you have pieces of D2 and ATS-34 around, spark test them versus the "mixed-up" blade. (Grind on the tang). A touch or two on the grinder may settle the question.

[pjelect]

I thought of the spark test, Texasjack, but didn't get to it. I ended up taking the blade to 1200 and then a little polish. It shined right up like ATS-34. I pretty well suck at getting D2 to shine like that so I'm sure it is ,in fact, ATS-34. Thanx all for the suggestions. Pat