I think theory with the cold was not related to temperature differential embrittlement, but sulfur embrittlement in the fabrication process. In the case of the

I think theory with the cold was not related to temperature differential embrittlement, but sulfur embrittlement in the fabrication process. In the case of the steel in the titanic, the theory is that there was excessive amounts of suphur in the steel, which "coats" the grain boundaries between ferrite crystals in the steel and causes brittle failures. Modern steels add Manganese to counteract this effect. Sulphur embrittlement is worse at colder temperatures, but will not be effected by heating/cooling cycles unless the heating is so intense that you get past critical temperature and recrystallize the steel (~2300 F).