Am I a crack??

[viral]

I forged this from a bearing and I had it welded to rebar. I recall when I cut off the rebar there was some weld left that I thought would blow off as we were forging. I don't think it's a crack. And it's in a weird place. Is this scrap?

 

[Matt River]

Try sliding a sewing needle into it

 

[Lieblad]

...... ?

 

[Nathan the Machinist]

That looks like trouble to me. I'd flex it and see if it opens up.

If it doesn't grind off, it's in the steel. If you think it might be some rebar that made it in, you can etch it (hot vinegar will work) and see if it etches differently.

 

[viral]

That looks like trouble to me. I'd flex it and see if it opens up.

If it doesn't grind off, it's in the steel. If you think it might be some rebar that made it in, you can etch it (hot vinegar will work) and see if it etches differently.

So of it etches differently and is rebar, what would that mean?
Also if its a crack, what would make it crack down the center like that? Whats strange, is it was bigger and I ground some of it out. One thing I noticed while grinding it, was that this spot would start to rust and the rest of the blade was still clean. That's how I initially noticed it. Quite a strange occurrence.

 

[Yugami]

Different steels rust at different rates. Probably rebar or filler metal from the weld