Some terminology questions.

S

SurvivalDude

Joined
Dec 7, 2006
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What does annealing do exactly and how is it done?

What does normalizing do and how is that accomplished?


I know when heat treating you heat it up to a certain point. Quench it, then temper however many times it's required.

Where does the annealing and normalizing come into play?

I do also have another question about the cryo treatment.

I'm going to make a blade out of L6, just laser cut and ground. Could somebody please tell me if these steps are correct?

1. Heat to non-magnetic or recommended temperature.
2. Quench in oil until the blade isn't glowing anymore.
3. Let it cool to about 130F in the air within 15 minutes.
4. Do I do the cryo here? Inbetween quench and temper??
5. Temper in oven.
6. Or do I do the cryo here? After the temper?

I really want this blade to be almost all Martensite, I know that after the quench and temper there is still 20% Austentite or more unless you do cryo.

Could somebody please elaborate on this for me?

Thanks
 
SurvivalDude said:
What does annealing do exactly and how is it done?
Click to expand...

Annealing softens the steel to the point where it can be cut drilled and worked easily. The steel is brought to a high temp and cooled slowly.

What does normalizing do and how is that accomplished?
Click to expand...

Normalizing relieves stress's built up in the steel from things like heating while working and uneven cooling. Some steels like certain high speed tool steels shouldn't be normalizied. Not certain but I think the steel is brought up to a temp somewhere areound 2/3ds of the heat treat temp and held there for a period of time, determined by steel thickness. Then is is brought up to heat treat temp.

I know when heat treating you heat it up to a certain point. Quench it, then temper however many times it's required.
Click to expand...

That depends entirely on the steel. Many stainless steels and high speed steels use the 2+2 method Heat, sub zero quench, double temper.

Where does the annealing and normalizing come into play?
Click to expand...

Annealing should be how your steel comes from the factory. Normalizing is during the heat treat process.

I do also have another question about the cryo treatment.I'm going to make a blade out of L6, just laser cut and ground. Could somebody please tell me if these steps are correct?
1. Heat to non-magnetic or recommended temperature.
2. Quench in oil until the blade isn't glowing anymore.
3. Let it cool to about 130F in the air within 15 minutes.
4. Do I do the cryo here? Inbetween quench and temper??
5. Temper in oven.
6. Or do I do the cryo here? After the temper?
Click to expand...

I don't use L6 but I assume it is like all other steels that require cryo treatment and you would do it after the quench.

I really want this blade to be almost all Martensite, I know that after the quench and temper there is still 20% Austentite or more unless you do cryo. Could somebody please elaborate on this for me?
Click to expand...

The cryo converts austensite to martensite, (Or is that the other way around?) that is the purpose of that step
 
Thanks.

So after the quench I would do the cryo. Isn't the blade still around 900 degrees or so after the quench? Aren't you supposed to quench until the glo of the metal is gone?? Wouldn't it be dangerous dipping 900 degree steel into liquid nitrogen!?!?
 
Leave the blade in the oil until it is quite cool-Cool enough to hold in your bare hand. Then, put it in the LN2.
 
And then I temper as normal? Is there a need to temper more than once?

I'm not going to make this the hardest it can get on the RC scale. I guess I'll have to find a happy medium probably around RC56-58.


Any other thoughts anybody?

Thanks again!
 
If you have 20 % retained austenite after quench you've done something very wrong !!! Like hardening temperature way too high ! L6 should not require [or benefit much from ] cryo. If you cryo the blade must be tempered afterward !!...
 
I'm just curious about this too.

I was reading something and it said that bainite is stronger than martensite.

Why wouldn't I want the blade to be made up of bainite formations then??


Thanks
 
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