Factory carbidized Strider?

[Frapiscide]

I was cleaning out my Strider SNG today and noticed that the lock face was different looking from the rest of the lock bar cut. Looking at the side, I could see the familiar marks from water jetting, but the lock face itself looks different. I can't tell if this is carbidizing or not.

As you can see, the blade has worn through whatever that was.

Also, here's a picture of the blade tang.