I'm not a mettalurgist, nor a blade forger, but I did have an opportunity to use a cryo treatment for a investigation project here at work (I work at an R&D lab).
Some interesting articles you guys who may actually understand what is being discussed in these papers:
Cryogenic quenching of steel talks about austenite, martensite, etc.:shrug:
Another one about wear resistance improvement.
Other papers are available on their site. They do $100 per batch for cryo treatment. I'm sure you can fit alot of razors in a batch!
I had thougt cryo was just for stainless (ala Friodurs, etc.) but it looks as if carbon steel would also greatly benefit from this process.