Elmax or RWL 34

[HillBill]

Cryo quenches only increase the hardness of the steel, sounds lovely until you need to temper it back down to 59 anyways, so you lose the benefit. Cryo was only intended to be used to increase the life span of machine tools that will never be resharpened.

Heat treatment for Elmax and RWL is straight forward enough. If you have the proper equipment.

Heat it up and hold at a certain temp for a certain amount of time, quench it, temper it to desired hardness (elmax requires 2x 2hr temper cycles, RWL only requires 1 x 2 hours)... job done. The temps can vary... for example, different hardening temps can be used to enhance certain properties of the steel... you can HT to either have the max levels of corrosion resistance, or maximum hardness (which won't be as corrosion resistant)

 

[BushBob]

The main thing about heat treating these steels is that you need to stop air getting to them. You can do this by wrapping them in thick foil, but if you do you can't tell what temperature the steel is by looking at it.

It's possible to treat an air hardening, oil quenching, steel such as 01 with a blow torch because you can see what temp it's at by its colour (there's a good video from Gough Custom on this method).

To treat RWL 34 or Elmax yourself you'll need an electric furnace with an accurate temp control on it. These are expensive. This is why many people send these steels away to get them treated.

Cheers,

Bob

 

[HillBill]

Yeah i use stainless foil for that. Not cheap!! About £100 a roll.

 

[muddled]

Not that I'd expect anyone to do at home but vacuum heat treatment is ideal for the martensitic stainless steels to prevent oxidation. Cryo treatment transforms the retained austenite into martensite, there is a volumetric change between these two phases this is why it is done to stabilise these alloys. When size critical tooling such as cold rolls and dies are left on shelving for years they can change in size as austenite will very slowly transform to martensite over many years. I would imagine that in stainless blades the austenite as with tooling can be sites of failure, weaker spots. As Hillbill said it potentially inceases the life of these alloys...would any knife user notice if it was Cryo treated or not...