destructive test of a forge weld

[Jeff Amundson 35]

I think I know what's going on here, but I'd to hear other opinions. This scissors blade was an experiment to begin with. When I found some cracks, I decided to break it to see what was revealed. The first picture shows the tip end of the blade. It's a heat treated laminate of 1018 and O1. I used a little ferric chloride to clearly show the two alloys.

 

I sawed and ground the 1018 to remove it from a short section. Then I clamped the exposed stub of O1 in a vise and tried to create a peel in the weld. The O1 eventually broke.

 

I was happy how far the O1 bent before breaking. Even though the weld looks flawed, it resisted the peeling force. I was also happy with the look of the grain in the break. Note: the dark black stain on the broken section is from the ferric.

 

I'm guessing the O1 cracks are from forging it too cold. I was already planning to stop using O1, so the cracks helped me make the change faster. I know O1 can air harden, and I think I crossed the line with it. Looking forward to comments. 

[Alan Longmire 3,678]

O1 also cracks if forged too hot, but I think you're right.  Nice grain.

[Gerald Boggs 299]

Know nothing about O-1, but your weld is odd looking. It's like you scarfed one end but didn't the other. That perpendicular angle of most of the weld area made any welding  difficult. When doing a lap weld, both pieces need to have a short scarf tapering down to a fine point. If not, the non-scarfed piece will just cut into the other piece, as it looks to have happened here.

[Jeff Amundson 35]

5 hours ago, Gerald Boggs said:

It's like you scarfed one end but didn't the other.

There's no scarf in these pictures. I think you're looking at how the O1 broke. I scarf the butt end of the O1 where I have to blend it into the 1018, but that's not in these pictures. 

[Gerald Boggs 299]

Then all I can say is, I know nothing about O-1 :-)