Thoughts on my ideas to make the most expensive, legendary steel ever made.

Ill start off by saying I am not a metallurgist, Just a knife enthusiast who knows the most basic principals of making steel. Here are my completely hypothetical questions.

Question 1; I know that liquid nitrogen is used in the process of of hardening and improving the crystalline structure of steel. My question is, could one use superfluid Helium as an improvement? Liquid nitrogen is about -321 degrees fahrenheit, 77 in kelvin, whereas superfluid helium is about -453 degrees fahrenheit, 3.3 in kelvin. Superfluid helium also has zero viscosity and zero entropy which are the reasons why it is called a superfluid. Helium also does not react with any elements or form any compounds.

https://www.youtube.com/watch?v=2Z6UJbwxBZI

https://en.wikipedia.org/wiki/Superfluid_helium-4

Question 2; This is the more ridiculous question. Could one make steel using diamonds as the carbon content? I have heard that diamonds would disolve in a few molten metals.

Question 3; Could either of these techniques have any effect on the strength of the steel. I know this is stupid but I feel like diamonds could form a better crystalline structure and give better control of carbon content. As for the Superfluid helium, I have no idea what it would do.