Overshoot temp with high carbon

S

sharkeater

Member
New to knife making and may have over shot the desired temp by 300°-400° on the first go round. Was trying to do it off the steels coloring. Can barely get it to 55 HRC (file) after 3 heat treat attempts. 80CrV2 quenched with canola. Do I need to spring for Parks 50? What am I doing wrong?
 
I normalized to 1500ish. After it cools, put back into gas forge then up to what I thought to be 1500-1600, then quench in canola. I have no way to check temp so I was going off color of metal. May have overshot both normalize and austenitize. Didn’t make it to temper step. A 55 HRC test file bit into it.
 
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sharkeater said:
I normalized to 1500ish. After it cools, put back into gas forge then up to what I thought to be 1500-1600, then quench in canola. I have no way to check temp so I was going off color of metal. May have overshot both normalize and austenitize. Didn’t make it to temper step. A 55 HRC test file bit into it.
Click to expand...
Might have been a bit too hot, probably didn’t soak long enough. That would be my guess. When I was using my forge to heat treat, I would bury the edge of the blade in a tray full of sand. It keeps it stood up, and keeps the edge from warping, and more importantly, overheating. I would let the spine get hot, then lift the blade up out of the sand. The edge will heat up very quickly. It will allow you to get a more even heat before quench, without burning the edge up. I would shut the forge off right before I lifted it out of the sand. That process, and using a magnet will give you good results I think.
 
Normalizing at austentizing temperature won't do much? 80CRV2 normalizes at 1600-1650.

knifesteelnerds.com

How to Heat Treat 80CrV2 - Knife Steel Nerds

How are you supposed to heat treat 80CrV2 when there are so many conflicting recommendations? Is the steel any good in the first place?
knifesteelnerds.com knifesteelnerds.com

Depending on where you got the 80CRV2 from, normalizing/annealing/DET Annealing may be better to get the steel into a better structure for heat treating, even with stock removal. AKS steel has the steel ready to go for heat treating if you are just doing stock removal.

I do 1650 Normalizing, 1400 soak for 30 min, followed by a slow cool for around 30-40 minutes down to 1200, then air cool (DET anneal). Austentizing is 1525 soak for 10-15 min, then quench in Parks 50 or AAA oil. I usually use ATP641 to coat for the Austentizing cycle and stainless foil for the normalizing/DET anneal cycle due to decarb.

80CRV2 decarbs a LOT!!! So your testing may be showing the decarb on the blade, where it could be hardened in the middle. I believe there was a batch of 80CRV2 a while back that wouldn't harden properly, even with extensive cycling.
 
Edwardshandmadeknives said:
Might have been a bit too hot, probably didn’t soak long enough. That would be my guess. When I was using my forge to heat treat, I would bury the edge of the blade in a tray full of sand. It keeps it stood up, and keeps the edge from warping, and more importantly, overheating. I would let the spine get hot, then lift the blade up out of the sand. The edge will heat up very quickly. It will allow you to get a more even heat before quench, without burning the edge up. I would shut the forge off right before I lifted it out of the sand. That process, and using a magnet will give you good results I think.
Click to expand...
Thank you. All good to know information. I will definitely try this technique.
 
Taz575 said:
Normalizing at austentizing temperature won't do much? 80CRV2 normalizes at 1600-1650.

knifesteelnerds.com

How to Heat Treat 80CrV2 - Knife Steel Nerds

How are you supposed to heat treat 80CrV2 when there are so many conflicting recommendations? Is the steel any good in the first place?
knifesteelnerds.com knifesteelnerds.com

Depending on where you got the 80CRV2 from, normalizing/annealing/DET Annealing may be better to get the steel into a better structure for heat treating, even with stock removal. AKS steel has the steel ready to go for heat treating if you are just doing stock removal.

I do 1650 Normalizing, 1400 soak for 30 min, followed by a slow cool for around 30-40 minutes down to 1200, then air cool (DET anneal). Austentizing is 1525 soak for 10-15 min, then quench in Parks 50 or AAA oil. I usually use ATP641 to coat for the Austentizing cycle and stainless foil for the normalizing/DET anneal cycle due to decarb.

80CRV2 decarbs a LOT!!! So your testing may be showing the decarb on the blade, where it could be hardened in the middle. I believe there was a batch of 80CRV2 a while back that wouldn't harden properly, even with extensive cycling.
Click to expand...
Shhhhew…, thats quite the process. Thank you for the information. lI’ll try anything to get the best result possible. I’ve been saying it for a while but it seems like I need to invest in an oven. Those timely processes seem like I’d go through a lot of gas.

I buy all my steel through AKS. I made the mistake of buying low quality stock early on. Lesson learned!!
 
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