26c3 strange etch problem

[Willie71]

I posted this knife in the what’s going on in your shop thread, but this probably deserves its own thread.

The knife is 26c3, purchased from AKS, or it might have been a sample that Chuck sent me a while back. This was before covid. I was trying to increase hamon potential, so I put did two grain refinement cycles at 1450f, iirc. I did a partial grind, like a Sabre grind, clayed the blade, and heat treated at 1425f. I think I did a 10 min soak. I quenched in DT-48. I tempered to Rc64. I don’t remember the tempering temp, but I did start low, and walked up over 3 tempers. I checked Rc hardness on the tang, where I had no clay.

The blade was sanded to 1000grit, after grinding down to 0.005”, ffg. Easily 0.020” ground off at the thinnest point near the edge. Decarb should not be an issue after this much grinding. I have used this technique with W1, W2, 1095, hitachi white, hitachi blue, 1075, 1084, 1085, and now 26c3.

I did a couple hunters/camp knives in 1085, one done at 1460, one at 1450, several years ago, using the same grain refinement and u der austenitizing, which has worked in other hypereuctoid steels to bring out more activity.

the 1460 turned out like this:

The one at 1450 had a more washed out look. More like the 26c3.

I’m interested in anyone’s thoughts on why it goes washed out and cloudy, and not in a good hamon way, beyond the obvious over etch in the top knife.

Larrin D DevinT

 

[Willie71]

Quick addition. It’s strange. The knife feels like it has a film on it, like wax, or lard. That usually means decarb to me. I cleaned it well with acetone, dawn dish soap, and brake cleaner. No difference with any of them.

 

[Tom Lewis]

Since no one else has replied, I will give my thoughts. First, very nice looking knives. If you used the same clay, etching and polishing, and heat treatment that gave you success in the past, then the only thing I can think of is that you don't have 26c3 steel.