Jump to content

Properties of O1, I'm stumped


Recommended Posts

Can someone give me a quick tutorial on heat treating O1? I have a pile of it in 3/8, 1/2, and 5/8 round and some in 1/8 flat. I have made half dozen blades with it to some success, but half end up with hair line cracks that creep along the surface. I initially thought that I might have been forging it to cold (still entirely likely) but I made a blade with flat stock by stock removal so never a hammer swung and I ended up with the same problem. Another potential issue might be anealing as I don't have a grinder so I have to soften this stuff up to file it to shape. On the up side I have some 1084 to keep me busy, I find it to be FAR more forgiving, or at least more suited to my situation.

Link to post
Share on other sites

Are you using water to quench? With 5160 I've never had any problem, but quenching O1 in water may be causing the cracks.

Link to post
Share on other sites

If it were me I would go ahead and snap one that is already cracked and take a look at the grain size. O1 does have a few issues with getting too hot. It seems to be very prone to carbon loss at high temps and I have gotten grain the size of beach sand if I didn't normalize before ht. Also you will want to temper immediately.

Good luck

Link to post
Share on other sites

Hmmmm. I did normalize, or at least I did what I think is normalizing for O1. I am not sure how much time passed between the quench and temper. I will try to remember that.

Link to post
Share on other sites

O-1 can self-destruct if you wait too long between the quench and temper.

 

Several years ago, I helped my brother-in-law forge an integral from round stock. We followed all the steps through quenching. He said that he had company coming and needed to leave. He would put in the oven when he got home (5 minutes away).

 

Company was already at his house, and he forgot to put it in the oven. Next morning, it had so many cracks in it that it looked like a spider-web.

Link to post
Share on other sites

I've worked thousands of blades of O-1 over the years but only had one batch do the micro-crack disaster. Never did solve exactly what happened.

I currently have a batch of several hundred almost ready for the salt bath in a couple days, I will hold out a handful to for a delay-to-tempering-test. It will probably be something like 6 hours, 24 hours, 48 hours. Maybe I'll learn something! if so I'll pass it on.

I concur that 1084 is a more predictable steel for non-technical settups.

I think it was Kevin Cashen who had on the net a thorough & extensive document on fine tuning the complexities of working O-1, but last time I looked the page was gone, I'd love a copy if anyone has it preserved.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...