Edge Quenching O1

[hosana]

:confused: While working on a new O-1 blade, I decided to try edge quenching for the first time. I heated it to a non-magnetic state then submerged the edge in about 3/8" from the cutting edge. Following all heat treating steps as I have in the past, I began to finish the blade. Today was the day to etch the blade to bring out the quench line. After soaking in a etchant solution and cleaning the blade, I began polishing the blade with a 800 grit paper, but no line. The line not being there doesn't bother me. What's bothering me is that I can't get rid of what appears to be a leopard print pattern in the steel.

WHAT AM I DOING WRONG???? Please Help!!
Mike

[AwP]

O1 isn't known to be a good steel for quench lines, since it's deep hardening. The hardened area usually fades into the unhardened part rather then a sharp line. I'm not sure what you mean by the leopard print, got a digital camera or a scanner?

[hosana]

No I don't have photo capabilities. After looking at it under a magnifying glass, it seems to be small piths in the steel. Extremely shallow, but noticable in the right light at the right angle. I think I'll take a 600 edm stone and see if it will disappear.
Mike

[SKIVIE]

Mike, Most guys etching 0-1 are trying to get that antiqued finish. When you say pitted slightly im sure were talking about the same thing. Like Andrew said, it is tuff to get a nice hammon line with 0-1 but not impossible. Ive had some that have turned out really nice but in doing so the entire blade has an antiqued etch finish to it. Hope that helps some.

Shane

[hosana]

Thanks for the help. I've decided to go with this finish. I'll post a picture when it's complete.
Mike

[David Peterson]

I use O1 a lot and thought I might be able to contribute a little. It's sure possible to get a hamon line on O1, but it is not as pronounced as the other steels I've use like 1095. The line on O1 is more like a fading discoloration than a defined line. It may be hard to see in the picture, but it was the only one I could find on short notice. The second picture is the 1095 hamon that is very defined.




The line in O1 shows up a little better when I etched it in vinegar, but never really gets as good as the other steels. It doesn't mean you shouldn't differentially heat treat O1, just don't expect much to show.

In reference to the spots you're seeing on the steel... they may be from the quench or possibly bad steel. I had a batch of 1095 that showed that same problem. I left the blade thick before the HT and ground out a lot of the steel after. I just made sure I kept the steel from getting too hot. I thought it might be from the oil splashing on the blade as I quenched, but I never really found conclusive evidence that it was the problem. Are you pre-heating the oil to 125-150 degrees? I use vegetable oil at 125 and it seems to show a really nice line in O1. Hope this is useful.

-Dave

[TikTock]

I get crazy lines every time with 1084 and 1095 but never with O-1. I dont even try anymore. The pitting you describe sounds like it may just be scale or surface blemishes caused during heat treating. Try wrapping some 100 grit around a file and simulate draw filing and see if they go any deeper than the actual pit. If so, you may have a problem. Otherwise, its just HT pitting and you can grind or sand it out with some serious elbow grease and a whole lot of patience. It sounds to be like you progressed through grits too fast and may have removed scratches but not evened the surface. You want to take down the entire surface, not just the low spots. Think of it like trying to rub out a divot in an ice cube. if you just rubbed in one spot, you would end up with just a more rounded divot. You need to slice that baby.

Blade finish has come slowly to me. I am still only now realizing how much time I save if i take it to where I think it should be, then take it more than i think it needs. Often, it still needs more. Theres nothing like finding a stray 200 grit scratch when youre starting 800 to ruin your day. If you just rub on that one spot until its gone, you end up with worse than a scratch because now you have a concave spot thats at least as deep as the scratch.