OK, I want to offer this real situation that happened today and see what you guys think. I have an idea of what the problem was, but I thought it might be good to analyze the problem and see if we can figure it out based on what we know about how steel behaves.
Some of us makers set up at the Big Buck Classic in Little Rock where we forged and visited with the public, basically introducing the craft to the attendees. It's a beautiful, bright sunny day. It's now time to start forging a blade and It's my turn. One of the less experienced makers insisted that I use his bar of steel. I get the blade about half forged and all of a sudden I look down and there is a glaring crack in it. Honestly, I am shocked. I have never, ever, had a blade crack while forging. A few suggested that I forged it too cold, but I am careful about such things and did not believe that to be the case. So I cut it off and started another. This one seemed fine.
The next two guys forged, or should I say tried to forge a blade using the same bar of steel. When one got finished, he just handed it off to the next guy. Both were experienced or closely watched by experienced forgers and both were plagued by unexpected and shocking cracks in their blades. When I say unexpected, I mean that the cracks were in the edge, the spine, the ricasso of all places, and some running the length of the blade. You could actually see some cracks form as it was being hammered while red. Now, tell me that's not shocking.
Like I said, I think I know what the problem was and why. Not be a smarty britches, but I figured this is a good thing for us to figure out here. So lets let it sit a day or so and see if you guys come up with the same thing. I will answer some questions to be fair in case I have left out something that is a vital clue. Lin