[Russell White]

I need advice on quench lines after etching in ferric chloride. I etched a blade of E52100 in ferric choride after edge quenching three times and tempering. It has a quench line, a transition area, and a darker area. The blade was heated fully to 1500 and soaked 20 min for first quench. Then heated in oven to 1500 and soaked about 5 minfor the second two quenches. The blade is 1 inch wide and four inches long. I used a regulator block in mineral oil to quench just over the bottom third of the blade. The blade was final ground and hand polished to 600 grit before etching. It has an orange peel look in the transition area after etching and I suspect that it has hardened on the spine. Any advice on the orange peel texture or the heat treat would be appreciated. Thanks,

Russell White

[BrionTomberlin]

Hello Russell. The orange peel as you describe it at the transition area could be alloy banding. It sounds like you did everything correctly and yes the spine may have hardened. Since 52100 has been known to harden in air in small sections. You may need to draw back the spine with a torch and of course the tang, in a water bath. You will not get a hamon so to speak with 52100, more of a diffuse line or area of transition. Do you have pictures?
Brion

[Russell White]

I did not take pictures, should have just wasn't thinking. I repolished with 400 then 600 grit. It was not very deep. Then took blade to a friends tool and die shop today and had him to hardness test it for me. I was surprised to find the cutting edge side of the ricaso 59.5 RC and the spine 36 RC. The blade cut rope very well and whittled a point on seasoned oak shovel handle with no problem. Could the orange peel look have come from decarburized steel on surface? I left the cutting edge thick before hardening but the spine was almost finished size. Thanks,

Russell White

[BrionTomberlin]

Yes Russell the orange peel could have been decarburization. Especially if you were able to sand it away. It usually does not go very deep. Since I usually do finish grinding after heat treat, I seldom have a problem with it. Except for certain steels, 9260 being one.

With those Rc readings you should have a good knife. Good work.
Brion

[Russell White]

Brion, thanks a lot for your input.

Russell White

[BrionTomberlin]

Russell, you are very welcome. Keep up the good work.
Brion

[ABS Webmaster]

Brion

I am looking forward to your demonstration at the 2012 Heartland Hammer-In in Topeka next weekend on Hamons.

[BrionTomberlin]

I am looking forward to seeing everyone. It will be a good one Dan. Looking forward to seeing you and Sally.
Brion