Hello everyone! Its been a few years since ive posted or lurked around here. Heres my problem that hopefully someone can direct me in the right direction. I have been doing sample heat treats with 440c .150x1"x1.25" as my piece to break apart And look at grain structure. For my procedure Clean 440 with acetone and insert into 309 foil double crimped Place into a pid controlled home made kiln Turn on and ramp to 1400 deg. F for 10 min Then ramp to 1900 deg. F and soak for 30min. Remove and plate quench After a few minutes I put it in a vice and break. So far I've done 5 test coupons all with different Temps and soak times and every time the grain looks coarse. Please note I'm only changing one perameter per test. Ive done alot of research on the web and reading the knife engineering book. All tests were held at 1400 for ten minutes except for one at 1400 for 15 min. Obviously I'm trying to refine my grain structure to yield the steels full capabilities. What am I doing wrong? Any help would be greatly appreciated!! Thanks Eric Here are 5 pics of the test pcs
