Heat treating

[4CIW]

I'm still new to this game and looking to ensure that I will have the results I'm looking for. As I understand the normalizing process, it's an annealing process applied to ferrous metals/alloys heating the steel to 20–50 °C (68-122 oF) above its upper critical point, then soaking it for a short period at that temperature and then allowing it to cool in air.
NJSB suggests that the normalization for 80CRV2 follow a 3 cycle heat differential process prior to the hardening/quenching stage. The first cycle indicates a working temp of 1650F for 10-15 minutes (duration reflecting blade thickness). My question is, do I take a blade to 1687F soak for 2-3 minutes and allow to completely air cool then proceed with the prescribed 3 times/temps from NJSB?

 

[vlegski]

I'd suggest visiting site called Knife Steel nerds and view their recommendations. Good information on normalizing, annealing and grain refinement cycles. Ive had good success with his numbers and they are based on his testing.

 

[Absinthe]

Here is one of his YT videos where he actually does forge heat treating instead of relying on furnace

 

[opaul]

I'm still new to this game and looking to ensure that I will have the results I'm looking for. Anderstand the normalizing process, it's an annealing process applied to ferrous metals/alloys heating the steel to 20–50 °C (68-122 oF) above its upper critical point, then soaking it for a short period at that temperature and then allowing it to cool in air.
NJSB suggests that the normalization for 80CRV2 follow a 3 cycle heat differential process prior to the hardening/quenching stage. The first cycle indicates a working temp of 1650F for 10-15 minutes (duration reflecting blade thickness). My question is, do I take a blade to 1687F soak for 2-3 minutes and allow to completely air cool then proceed with the prescribed 3 times/temps from NJSB?

I do normalize my blades prior to heat treat.

This is from Alpha knife supply.

80CrV2 Carbon Steel Information and Composition​

Condition:
This alloy been properly annealed and is in the soft condition. You do not have to do any non-standard wasteful processes before heat treating. The steel must be heat treated to get to a hardened state. Follow the heat treat recipe and the steel will harden.

80CrV2 Heat Treat Information:​

Austenitize: Heat to 1,545°-1,615° and hold for 5 minutes. Quench in oil.

Temper: Temper twice for two hours each time. Use the chart below to select the tempering temperature.

Ratings:
57 = Maximum Toughness
NT = Maximum Edge Holding

The rating scale is 0-100, 0 being minimum and 100 being maximum. The ratings are the maximum potential of the alloy. If the value shown is "NT", the testing has not been performed. I do not recommend heat treating to the maximum value. Choose a heat treat recipe that results in the attributes you want.

Thank you to Dr Larrin Thomas for all the testing he performed and information he has provided. Buy his book Knife Engineering to learn more about knifemaking.

 

[jmforge]

I probably would not follow the adivce re the high 1615F austenizing temp.

 

[soundmind]

For my normalizing, thermal cycling, and quenching temps I did a 120 second count hold for each.

I didn't go that high either on my austentizing temp. But I have a gas forge so can't say for sure. I shot for what I thought was just above 1500.

Still new myself, but I carried this blade for a year until I gave it away. And will use the same process again on the rest of my 80CRV2 until I get an electric furnace.

I tempered it at 365F.

 

[soundmind]

Larrin's book and videos are super helpful.