Steel

The refractory properties of rhenium make it indispensible for aeronautical tech

Whipped Cream Difficulties has a post up about battleship steel. pigpen51 comments:

I made steel for a living, for over 35 years. And have to wonder if the steel that we made, especially from virgin material, was low background. Since all of the materials would have been mined from underground, it should have been shielded from radioactive fallout.

We actually had to check the radiation level of some virgin materials coming in from certain parts of the world. Mostly things like Tellurium, Hafnium, and other rare elements that we used in making super alloys for jet engines. We used a Geiger Counter to check the metal before letting it come into the plant. And we also kept some of them locked in a safe, like Rhenium, due to both the possibility of contamination but also the extreme cost.

I melted heats of 8,000 lbs. that were worth 10 million dollars, due to the amount of both Rhenium and the expertise to melt the heat in the correct way, under high vacuum conditions. This alloy in particular was used in the hot section of jet engines. It kept it’s strength very close to it’s melting point, and the hotter the engine could run, the more efficient it would be.

He mentions my old friend Rhenium. Huh.