SK Monosteel fun

[Pie]

Sooo I like polishing stuff. I tried polishing an SK steel higo on some jnats, failed miserably.

Ended up just going synthetic and polished up to a passable, but not perfect mirror finish

(Bigger higo, same steel)

I couldn’t resist seeing what jnats would do, and I noticed a bit of weird texture in the blade near the edge, and some uniform difference in where a cladding would typically be. After going through most of my stones, landing on a fairly mysterious hard suita, I ended up getting what looks like a cladding line and some stuff that doesn’t look like banding that I’ve never seen before. Still sort of mirror polish.

Now comes the fun part, a super ghetto lemon juice hot knife etch - surprisingly effective, and holy damn look at this

Does anyone know what’s going on with

1. The difference in the way the steel polishes at the top and bottom of the bevel? It’s a pretty consistent curve, I don’t think I could follow that if I tried so it can’t be me doing something.

2. What that craziness in the “core steel” looking part of it is? I can’t feel any texture to the touch, and It came off a 5k base polish, so there’s no way it can be scratches.. could it be impurities?

All in all a weird experience. Cool for sure, but weird. Didn’t expect to see a monosteel knife do stuff like this.

 

[Benuser]

The only thing I've noticed when sharpening SK steels is their coarse structure, even when taking and holding highly polished edges without any problem, resulting in a remarkable bite. No idea where it comes from.
About the supposed impurities: over time, the tolerances seem to have drastically been reduced.

 

[natto]

Etching after fine polish is used in metallurgy to show carbides and and the different phases or microstructures. @Larrin shows some microscopic pictures at knifeSteelNerds.

 

[Troopah_Knives]

I'm fairly sure the top line is differential hardening (some call this auto Hamon). It could also be that the line closer to the edge is differential hardening and the one further up the blade is decarb but it is a little hard to tell based on the pictures.

The structure you are seeing in the steel after each is almost certainly alloy banding. Different forging processes post solidification can cause different-looking carbide segregation.

I hope that answers your questions!

 

[Pie]

I'm fairly sure the top line is differential hardening (some call this auto Hamon). It could also be that the line closer to the edge is differential hardening and the one further up the blade is decarb but it is a little hard to tell based on the pictures.

The structure you are seeing in the steel after each is almost certainly alloy banding. Different forging processes post solidification can cause different-looking carbide segregation.

I hope that answers your questions!

This 100% answers my questions. Thank you! It’s not the prettiest banding out there but it’s there. Cool, at least I know what’s going on .