cpm s90v

jblauvelt

Well-Known Member
I have a heat treating question. I am new to this steel cpm s90v) and heat treating in general. I ground a couple of fairly thin 9" fillet blanks. I am thinking that something went wrong during my normalizing cycle. Perhaps brining it up to temp, holding, and then letting it cool in the furnace may allow it to cool too quickly. (instructions says ramp down 25 degrees per hour to 1000) At any rate, I got a bad bend upon quench. (Oil) I figured I could fix it during a tempering cycle but ended up snapping it. Any suggestions would be appreciated.
Thanks
Jim
 
I didn't realize that. After forging, I annealed, then ground and drilled for pins. then ran a normalizing cycle. then a hardening cycle. I will try the plate and compressed air method. I imagine that the plate sandwich will keep it from warping.
 
You are forging S90V? Are you heat treating/annealing/normalizing with the forge also? You are new to S90V? What steels are you familiar with?
 
yes, I forged in a gas forge, annealed, normalized and hardened in a heat treat kiln. up to now I have only been using simple carbon steels. I am totally green. I am getting the feeling by some of the reply's here that forging s90v is a no no. I started with stock that was 3/16" thick and slowly forged it thinner with a taper. The first blade warped badly in an oil quench. The second blade I plate quenched and I am very happy with the result.
 
Can you give approximate temperatures for the forging, annealing, normalizing, and hardening?
 
Can you give approximate temperatures for the forging, annealing, normalizing, and hardening?

well when I forged it, I heated to the limit of my gas forge, 2100-2300. Then drew it out with a trip hammer, short trips in and out until it was drawn and tapered. I annealed it at 1650, held for 2 hours and let cool in the oven. Normalized at 1200 for 2 hours then let it cool outside the kiln. Hardened at 2100 for 10 minutes and plate quenched. During the normalizing and annealing heats, the blade stayed very straight. when I was running the hardening cycle, it came out of the kiln with a large bend in it. The plate quench straightened that out. There was some very minimal distortion in the edge but the spine stayed straight. After hardening, a 65 rc file would just scratch it but a 60 rc file would not. Tempered at 450 for 2 hours twice.
 
How did you arrive at those temperatures? The normalizing and annealing seem low, and may not have done much on a steel like S90V, or at least not done what you intended. I've have little experience testing hardness with files, but I generally hold them to have a wide margin of error, potentially even in experienced hands.
 
I took those temps off the Crucible web site. After forging, it did air harden. Drilling pin holes was impossible. After a normalizing cycle it became drillable and grindable. Yeah I'm sure the files I have leave a whole lot to be desired. The way I see it, as a hobbyist ya gotta start some where and broad data is better than none.
 
Don't Quench!

. At any rate, I got a bad bend upon quench. (Oil) I figured I could fix it during a tempering cycle but ended up snapping it. Any suggestions would be appreciated.
Thanks
Jim

I'm certain it bent when you oil quenched it. Long thin blades are hard to keep straight under the best conditions, but the oil quench cooled it way too fast!

You need to air cool it in still air. See the attached data sheet.

https://www.alphaknifesupply.com/Pictures/Info/Steel/CPMS90-DS.pdf

Joel
 
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