Another one for the scrap bin.

[weo]

Hello all. I hope y'all are having a better day in the shop than I did today. Following a decent day of forging yesterday, I started grinding this blade that was from the billet from this thread:
O1 welding blues (pics added)
I noticed a slight bow in the blade, so put it in the vice to straighten it a bit (this is all prior to HT, BTW) and heard/felt another 'tink'.

I'm fairly sure I didn't grab the blank there with the tongs when the steel was over 1600F. The blank was a bit over 0.125" thick, would grabbing it with flat jawed tongs harden the blade if I had?
So now I'm wondering if the piece of steel that I thought was O1 was actually something different. Or will O1 air harden?
Any ideas?
On the plus side, the edge of the blade looks like it's only 15N20, and not the 15 layer piece that I thought it was...so I didn't lose the waterfall I'm going for.

 

[Willie71]

Hello all. I hope y'all are having a better day in the shop than I did today. Following a decent day of forging yesterday, I started grinding this blade that was from the billet from this thread:
O1 welding blues (pics added)
I noticed a slight bow in the blade, so put it in the vice to straighten it a bit (this is all prior to HT, BTW) and heard/felt another 'tink'.
View attachment 1357237
I'm fairly sure I didn't grab the blank there with the tongs when the steel was over 1600F. The blank was a bit over 0.125" thick, would grabbing it with flat jawed tongs harden the blade if I had?
So now I'm wondering if the piece of steel that I thought was O1 was actually something different. Or will O1 air harden?
Any ideas?
On the plus side, the edge of the blade looks like it's only 15N20, and not the 15 layer piece that I thought it was...so I didn't lose the waterfall I'm going for.

Did you normalize or stress relieve? Forging can impart a lot of stress in the steel. Both O1 and 15n20 will air harden a bit too. Probably not enough to cause this though.

 

[weo]

Did you normalize or stress relieve?

Thanks for the response, Warren. I'm pretty sure I did one cycle. This was the first of 3 blades I finished forging the other day, and I didn't turn on the Evenheat for thermal cycling like I've been trying to get in the habit of doing, so I was trying to determine 1600F by sight.

Both O1 and 15n20 will air harden a bit too

I've noticed this with 15N20 before when trying to file in the shoulders for the tang, and noticed it again today. I really need to burn this into my brain. Hopefully this post of yours will do the trick. It's amazing how some things tend not to stick, I guess I'm not as smart as I want to think I am.