- Joined
- Feb 16, 2010
- Messages
- 3,668
This is the second blade that I have HT with DDaveLarsen. Both blades are s30v. Here's the formula:
put knife in oven
ramp to 1650 and soak for 20 minutes
ramp to 1950 and soak for 20 minutes
plate quench for 2 minutes
Here's where they differed. The first blade never got cryo, and wasn't double tempered for several weeks. The second blade got tempered, cryo, tempered and tempered.
On the first blade, 24 hours after plate quench it warped about 1/32".
On the second blade, 24 hours after the final temper it warped 1/64".
I'm certain they were perfectly straight after the quench. Especially on the second. I was paranoid about it warping because of the first blade. I probably checked it for warpage fifty times before I noticed the warpage. Final temper was Monday at 1pm. Tuesday morning it was still straight, but I was working up the nerved to starting sanding. By 5:30 when I left work for the day it was warped. It hasn't gotten any more warped since and I have proceeded to sand it.
Here's the only thing I can think of. Inside the oven, the blade is in foil laying on top of two ceramic risers to keep it off the floor of the oven. Could this be the problem? Should it be flat on the floor of the oven?
put knife in oven
ramp to 1650 and soak for 20 minutes
ramp to 1950 and soak for 20 minutes
plate quench for 2 minutes
Here's where they differed. The first blade never got cryo, and wasn't double tempered for several weeks. The second blade got tempered, cryo, tempered and tempered.
On the first blade, 24 hours after plate quench it warped about 1/32".
On the second blade, 24 hours after the final temper it warped 1/64".
I'm certain they were perfectly straight after the quench. Especially on the second. I was paranoid about it warping because of the first blade. I probably checked it for warpage fifty times before I noticed the warpage. Final temper was Monday at 1pm. Tuesday morning it was still straight, but I was working up the nerved to starting sanding. By 5:30 when I left work for the day it was warped. It hasn't gotten any more warped since and I have proceeded to sand it.
Here's the only thing I can think of. Inside the oven, the blade is in foil laying on top of two ceramic risers to keep it off the floor of the oven. Could this be the problem? Should it be flat on the floor of the oven?
