Mass General subway stop welding consultation

Used as the exemplar case where 1900-era steel chemistry matters for solidification cracking — Tom checks manganese-to-sulfur ratio on old steels, not just hardenability/hardness.

Solidification cracking — it says keep the proper manganese-to-sulfur ratio. Well, this was a problem back in 1920, when we had high sulfur like 0.05 sulfur. The proper ratio, if you go back and read a metallurgy text from 1920 or 1930, is that the manganese-to-sulfur ratio has to be greater than six. If I have 0.05 sulfur, six times that is 0.3 manganese. Most steels have 0.3 manganese; many of them today have one percent manganese. So it's not really a problem, unless you're doing something like the Mass General subway stop. When they call me up, I say, what's the composition? If it's a 1900 piece of steel, I would also start worrying about the manganese-to-sulfur ratio. It wasn't just hardenability and hardness — I would start worrying about some of this in the really old steels.