I have not heard of this. Most SS is only corrosion resistant if it is exposed to O2. For example, SS foundation bolts will corrode right at the concrete surface. SS marine fittings will corrode if they are in an area where the water does not circulate and becomes O2 depleted.
Q: Does this "Maraging 314M single crystal stainless steel super alloy" require exposure to O2 to maintain its corrosion resistance?
ice
We were doing alloy research for single crystal applications. Most of our alloys were nickel based, but we did experiments on just about anything.
To do metallography, a test piece is mounted in a type of epoxy. The piece is then ground flat and polished to a near optically perfect surface. That meant no visible deformaties at 1000x. Mirror quality. Then, an etchant was applied and the microstructure of the crystal would become apparent. That sample was then put in a microscope with a camera on it. We would then take a picture and look at the dendrites and interdenritic areas.
One day I was given some 314M to make a crystal out of. I did and when I went to etch it, nothing would touch it. I had access to every chemical known to man and even hydroflouric acid charged with 30 percent hydrogen peroxide wouldn't touch it. I left it in over nite in aqua regia and supercharged aqua regia. Nothing. Now, etching a regular sample takes about 4 seconds once the right etchant discovered. You would just swab on the acid and just before it started to burn, you would rinse it off. This stuff was metal legends are made of. Other SS alloys could be etched, but never made it to production because the nickel based alloys were superior.
The sample is probably still in a locker somewhere. My boss had no interest in the crystal because he couldn't make jet engine parts out of it if it could not be etched as we needed to see the orientation in 3D of the crystal of each part we cast.
Another project that was cool was using titanium sponge to store hydrogen gas in. They filled a tank with sponge, pressurized it to about 1000 psi with hydrogen and then shot it with a 30-06. All that happened was the '06 punched a hole in the tank and a little tiny flame was burning at the hole. The sponge absorbed the hydrogen so once the pressure was removed the molecules intertwined and the hydrogen was released slowly. To compare, they also shot a tank with no titanium in it and it blew up like a bomb.
That's probably stashed somewhere at Howmet, too.
