Seawolf submarine hull cracking

Recap from an earlier session. Over-matching by 30–40% combined with insufficient preheat for the resulting higher hardenability. Used here as the lead-in to the Helms Project — "this still occurs on a fairly regular basis."

I'm going to start giving you some examples of classical failures. We've talked about the Seawolf. On the Seawolf they ended up with a very high material strength in the weld metal — too high. It was over-matching by about thirty or forty percent. You ended up not necessarily with an inherent problem in the weld metal, but with higher stresses and higher hardenability, and they didn't have enough preheat for that higher hardenability to get the hydrogen down to a low enough level.