Lost a blade to a cold weld I trusted too much

I was working on a chef's knife last Tuesday in my shop outside Toledo. I stacked a billet of 1084 and 15N20, brought it up to forge welding temp, and hit it on the anvil about four times before I heard that sick crack. The whole thing delaminated right down the center, and I had to scrap 6 hours of work because I got cocky and rushed the flux after a cold soak. Has anyone else had a weld fail from not letting the billet heat evenly all the way through?

3 comments

3 Comments

pat_harris14d ago

That "cold soak" part really jumps out at me, because that's exactly where I've seen my own welds fail too. How long did you let it sit between heats before you went for the weld? I've noticed if I pull a billet out and let it sit for more than about 20 seconds on a cold anvil, the center drops way below welding temp even if the surface still looks good. @abby_fisher is right about that sound being unforgettable, I had a 15 layer billet do the same thing last spring and I still check every weld three times now before I put any real hammer to it. Did you try running it through the forge again to see if it would rebond, or did it just fully separate on you? Sometimes I've had luck bumping the heat back up and fluxing again, but only if the crack is clean and not full of scale.

abby_fisher15d ago

That "sick crack" sound is the worst, I still hear it in my sleep sometimes.

morganl7115d ago

Right? That noise just sticks with you...