[keithwalton]

Ah for cryogenics, steel's worst nightmare. It is amusing how easily you can snap a rod of steel in half when its cooled to ~80k
Pretty much everything can be 'broken' easily when you get it cold enough.
I did chuckle when the first problems began to arose with steels suffering from fractures at low (ish) temperature. Intuition would suggest increasing carbon content to make it harder / stronger (raises max loading under normal conditions so less likely to fail) but with ultra low temperature applications that is the worst thing you can do! (It increases the temperature to which steel becomes brittle, hence sudden failure)