Thread: The correct Blade hardness 01 for razors

What do's the salt do??

Originally Posted by skipnord

Everything I know about heat treating, I learned from Mike Blue. Mike, if I get this wrong, or left anything out, feel free to correct me. With Salt, hold a 1490 for 10-15 minutes. Quench in 380 degree salt for 1-2 hours. Cool in still air. You are done.

If you're after Banite, as opposed to Martensite, that will work.

Originally Posted by pixelfixed

What do's the salt do??

Salt at 1490F is used to heat the blade. It is great for protecting the surface of the steel from oxidation, very even heating, and precise temperature control.

A different salt, at 375F - 450F, is used for quenching some steels. It replaces the oil in quenching, and allows for techniques such as martempering and austempering.

The salts are melted and liquid at temperature.

Guys, thanks for the help. I think I realized what I was mistaken
My midnight today in Russia Day Driver (Friday): I had a few drinks of vodka
Tomorrow morning I thought about all the information to make the table and ........ continue the conversation.

I think that my English - awful:

My Russian is even worse my friend, good information here for someone interested in heat treating like me!

Originally Posted by Tim Zowada

First, the blade must be properly normalized and spherodize annealed. Then,

If using a gas forge, for O-1:

1. Heat to 1500F - All "shadows" are gone. No soak at temperature. It is too easy to overheat in a forge. This is why I would prefer 1084 or 1095 over O-1 in a forge.
2. Immediatly quench in warm (160F) oil (Park AAA) - rapid agitation of blade.
3. Interrupt quench when blade reaches about 400F (pseudo martemper)
4. Air Cool to room temperature.
5. Temper at 380F two times.

With my salt bath stuff:

1. Austenize in salts 1490F, 10 minutes at temperature.
2. Quench in 420F Salt, 30 seconds rapid agitation
3.Air cool to room temperature
4.Temper 350F 1 hour
5. Freeze in Liquid Nitrogen - 1 hour, warm slowly
6. Temper 350 - 1 hour
7. Temper 350 1 hour

I think this is the best recommendation.
Many thanks to all.
I hope on earth clean faces will be more

01 does like a soak time but as stated unless you can control temp between 1450 & 1500 grain growth is a real risk.
My forge is dead simple so I triple quench 01, no real logic just trying to get most of carbon in solution and refine grain.
Someone will probably chime in and tell me this is not necessary. Read Kevin Cashen on matters heat treat.
Does anyone know if 01 would benefit any from cryo?

JG

http://www.hartsteel.com/index.html claim that they do it (Crio)

I'm hoping Mike Blue will weigh in on this. He knows more about metalurgy than anyone I know. My understanding from conversations with him about cyro is that it is only beneficial with stainless steels, and has absolutely no value with carbon steels, such as O1 and 1095.

Okay, I'm going to recommend a review of everything from beginning to the present point. Skip: you remember your lessons, what I will say next is part of the wide constellation of other factors that sometimes interfere with a good recipe that goes bad.

It has happened to me, as I'm certain to Tim as well. First question: Is this really O-1? If it's not following what we expect it to do, it might not be what GVIKzn was told it was. Sometimes the scrap yard or even the steel company can mislabel the material.

All the recipes expressed here are good ones and within the range of workable.

Tim uses cryo and I do not. That's not a critical factor now because I suspect the problem is occuring long before we get to that point in the process (that this may not be the steel we think it is.) If the heat treatment is done properly from the beginning (the heat history of the blade from bar to finished product), I personally do not believe that simple low alloy steels need to have the money spent on them with liquid nitrogen or the like. I am a cheap fellow. People who believe otherwise or have extra money may do as they please.

The edge could be difficult because the bevel angle is wrong.

Given the thin edge on a razor, overheating the edge is very possible, which will cause grain growth even during the thermal cycling attempts to prevent it. Unless good control is present, it's possible to take two steps forward and one step back. The grain could be well refined at the spine and body but keeps just missing the edge.

It is also possible that there may still be decarburization at the edge in the thin section because of the heat history of this blade, or the bar it came from and more material must be removed to get down to steel.

These are things that come to mind when the usual answers do not seem to take care of the questions.