I'm working out a protocol for 52100. Here are the steps I have so far with an explanation as to why the step is necessary. Any corrections or advice is appreciated.
After forging to shape, profiling, and straightening:
1) Normalizing: 1700F (20 min soak) w/ air cool to RT
2) Thermal Cycling for Grain and Carbide Refinement
1650 F (15 min soak) cool to black
1500 F (15 min soak) cool to black
1350 F (15 min soak) cool to black
3) Annealing--Not sure what to do here since I don't have an oven. Maybe just heat it to 1350F several times?
4) Rough Grind
5) Stress Relieving Cycle (maybe 1350 F or so?) and cool to black
6) Austenitize at 1500F w/ 15 min soak (a low temp in order to retain carbides) and quench in medium speed oil (AAA)
7) Temper two hours (x2) at 350F for slicers and 400-450F for choppers
What do you think? Any advice/corrections?
I suggest replacing all three of your thermal cycles with 1450. After reading this in the book "Knife Engineering" I performed several test batches in my kiln and sure enough the grain was much finer. Annealing isn't required. After normalization it is easily soft enough to file or grind. I'll let someone else chime in on your stress relieving cycle after rough grind.....couldn't hurt.
There's no reason to "anneal". When you do that it usually just adds another heat cycle pre-austenizing to put the carbon back in solution.
Karl B. Andersen
Journeyman Smith
|quoted:
I suggest replacing all three of your thermal cycles with 1450. After reading this in the book "Knife Engineering" I performed several test batches in my kiln and sure enough the grain was much finer. Annealing isn't required. After normalization it is easily soft enough to file or grind. I'll let someone else chime in on your stress relieving cycle after rough grind.....couldn't hurt.
Thank you for the feedback. I would not have thought to cycle three times to 1450. I'll have to do some experimenting as well.
|quoted:
There's no reason to "anneal". When you do that it usually just adds another heat cycle pre-austenizing to put the carbon back in solution.
Good point.
