You could weld it ( forge welding would be better), but probably won't be able to get it to look right due to the thin steel. What exactly were you doing when it cracked? Quenching? I have cracked a few when the oil was not quite hot enough. Also, if you lay it flat it in the oil, there is a greater chance of it warping and cracking. I put it in the oil with the blade vertical, like I am trying to cut the oil.