- Joined
- Jan 16, 2006
- Messages
- 386
Yes, CPM D2
I was fortunate to obtain a piece of CPM D2 recently and on another thread on this forum promised to report on first impressions. Crucible recently made a test heat on this steel to see how it would work out. Here is what I have found so far: This steel does have close to the same chemistry as convential D2 according to Crucible (Scott Devana) but is made with the CPM process. In general the CPM process should yield better properties, increased toughness in all directions, better corrosion resistance and allow for better heat treat response. This proved to be true for CPM 154 compared to the 154CM grade ( IMHO). I made a 4.5 inch drop pt hunter for the first test. Thickness at the spine is 0.135 and width is 1.1 inch at the widest part. It is finish flat ground from the spine to an edge thickness of 0.10. Heat treat was as follows: Coat with Turco, preheat to 1500, ramp to 1940 and hold half hour. Quench in front of a fan to room temp and then direct into LN2. Hold 2 hours and triple temper at 400. As quenched hardness was 64 and I did not detect any increase out of the LN2. Final tempered hardness is 62. Normal high temperature for D2 would be 1850 to 1875 but I have found that the CPM steels seem to benefit from a higher temperature so I went higher on the first test piece. RC 62 is also pushing the high end of hardness on convential D2 and a thin blade would tend to be a little chippy at the hardness in my experience. I sharpened the blade at 15 degree angle with a silicon carbide fine stone and stropped on loaded leather. So far I have not cut rope with it but as you would expect it will cut cardboard with ease for a very long time. I whittled some pine and twisted the blade out of the cut and there was no chipping from that. I did not chop with it. My conclusions so far are that it seems to be tough enough for a slicing type blade at high hardness. Edge holding I think will prove to be very good, as good or better than convential D2 and it has very nice finish qualities. It grinds and finishes like CPM 154, no surprise there. These are general observations and more work needs to be done. It will also be good to hear from others who try this one out. But so far it looks good. Phil
I was fortunate to obtain a piece of CPM D2 recently and on another thread on this forum promised to report on first impressions. Crucible recently made a test heat on this steel to see how it would work out. Here is what I have found so far: This steel does have close to the same chemistry as convential D2 according to Crucible (Scott Devana) but is made with the CPM process. In general the CPM process should yield better properties, increased toughness in all directions, better corrosion resistance and allow for better heat treat response. This proved to be true for CPM 154 compared to the 154CM grade ( IMHO). I made a 4.5 inch drop pt hunter for the first test. Thickness at the spine is 0.135 and width is 1.1 inch at the widest part. It is finish flat ground from the spine to an edge thickness of 0.10. Heat treat was as follows: Coat with Turco, preheat to 1500, ramp to 1940 and hold half hour. Quench in front of a fan to room temp and then direct into LN2. Hold 2 hours and triple temper at 400. As quenched hardness was 64 and I did not detect any increase out of the LN2. Final tempered hardness is 62. Normal high temperature for D2 would be 1850 to 1875 but I have found that the CPM steels seem to benefit from a higher temperature so I went higher on the first test piece. RC 62 is also pushing the high end of hardness on convential D2 and a thin blade would tend to be a little chippy at the hardness in my experience. I sharpened the blade at 15 degree angle with a silicon carbide fine stone and stropped on loaded leather. So far I have not cut rope with it but as you would expect it will cut cardboard with ease for a very long time. I whittled some pine and twisted the blade out of the cut and there was no chipping from that. I did not chop with it. My conclusions so far are that it seems to be tough enough for a slicing type blade at high hardness. Edge holding I think will prove to be very good, as good or better than convential D2 and it has very nice finish qualities. It grinds and finishes like CPM 154, no surprise there. These are general observations and more work needs to be done. It will also be good to hear from others who try this one out. But so far it looks good. Phil
