[QUOTE=Machka;13239089]Where's your proof? What happens at -51C?

Hydrogen embrittlment / failures can occur at room temperature.

You would not believe how much testing the equipment we used to build had to go through before it was passed... this is of most concern in the oil industry where you are dealing with high loads and pressures and where failure of a part could cause catastrophe.

Embrittlement can occur throughout the process of alloying steels and casting where hydrogen is introduced and can also be introduced during manufacturing and final fabrication.

I am not a materials engineer... just a guy who works with a torch.