Wondering about oil-quench.....

[richard rosvall]

I've been getting excellent results heat-treating and tempering O-1 using a formula posted here by Allen Blade. He recommends heating the oil for the quench to about 135 degrees. Fellow forumite Disco Stu sent me an article recently about clay-tempering in which the oil is heated to around 200 degrees. Would there be any advantage to using this higher temperature all the time? Thanks.

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http://rosvallent.com/

 

[Disco Stu]

Richard, I recently read an article that goes even farther to say that the oil should be around 400 deg. That the high temp ensures that all the martensite possible is formed. I'll try to find out just where I read it. It wasn't anything I set out to read, I just glanced at it and this caught my eye. Seems a little extreme to me. I keep thinking I must have read it wrong. Guess I'd better go looking for it.

[This message has been edited by Disco Stu (edited 06-02-2001).]

 

[E.V.Chavar]

For what its worth, I have been using Goddard's Goop to quench all of my damascus
and carbon steel blades. Got the info from his
book. The advantage for me is the I rarly do
large batches of blades and this stuff can be
used cold. I have treated quite a few blades
since mixing up my first batch and the blades
come out rock hard and so far I have yet to
crack a blade. Had some problems a while back
with warped blades quenched in various oil
mixtures, but as I have said, I have had no problems since switching to the new quenching
media

 

[richard rosvall]

Thanks, guys. Ed, I saw your post at the Custom forum and was hoping you'd come over here and give us new makers the benefit of your knowledge. Stu, if you ever find that article, let me know.

 

[Ron Peek]

That might have been an article on marquenching or martempering. The idea is to get the blade down to the hardening range as fast as possible, but then hold it at that temperature long enough to allow a maximum conversion to martensite. I think they usually use a salt bath for this, as that would be very close to the flash point for most oils. Tim Zowada has had several detailed discussions on this in various magazine articles.
Ron