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Cpm d2
- Thread starter Bear_Blade
- Start date
- Joined
- Jan 16, 2006
- Messages
- 386
Although CPM D2 has the same chemistry as D2 (except maybe 0.1% nitrogen added from the CPM process), the heat treated product is different from wrought D2. Wrought D2 typically has only 7-8% dissolved chromium whereas the CPM version has much more, I would guess more than 10%. So the CPM version would be more corrosion resistant. CPM D2 would have different carbides, including smaller, more wear resistant ones and fewer of the larger chromium carbides than D2. If you heat treat it the same way as wrought D2, I'm not sure you would end up with the same hardness either. Sometimes the CPM version of a particular steel ends up being a bit harder with the same heat treat.
Wasn't the reason why CPM D2 originally getting discontinued was because S30V is a better steel? Though seeing as to how CPM D2 is being heat treated to 62 rc while S30V typically to 59 rc, I'm not surprised that people are reporting the CPM D2 to be the better performer. My own experiments with S30V suggest much higher austenizing temperatures than what the datasheets recommend (for higher hardness) being more optimal for the kinds of knives that S30V is typically used in. In this case, S30V should in theory be more corrosion resistant and more wear resistant than CPM D2, with comparable toughness. In theory anyway.
Codt. Your theory seems to bear out at least with the 4 CPM D2 knives I have made. Since I have not used CPM D2 in the field I cannot give feeed back on actual corrosion resistance but just looking at the chemistry CPM S30V should win out there. As far as wear resistance CPM S30V at 61 held its own with CPM D2 at 62. My recent cutting tests on 5/8 rope show 30V to have noticeably better wear resistance even at a lower hardness. I don't know that CPM D2 will-- or is-- being discontinued due to competition with 30V. I think it is more of a lower demand and maybe some problems with the actual manufacture on the CPM version. Some grades just lend them selves better to the CPM process. Phil
Wasn't the reason why CPM D2 originally getting discontinued was because S30V is a better steel? Though seeing as to how CPM D2 is being heat treated to 62 rc while S30V typically to 59 rc, I'm not surprised that people are reporting the CPM D2 to be the better performer. My own experiments with S30V suggest much higher austenizing temperatures than what the datasheets recommend (for higher hardness) being more optimal for the kinds of knives that S30V is typically used in. In this case, S30V should in theory be more corrosion resistant and more wear resistant than CPM D2, with comparable toughness. In theory anyway.
Codt. Your theory seems to bear out at least with the 4 CPM D2 knives I have made. Since I have not used CPM D2 in the field I cannot give feeed back on actual corrosion resistance but just looking at the chemistry CPM S30V should win out there. As far as wear resistance CPM S30V at 61 held its own with CPM D2 at 62. My recent cutting tests on 5/8 rope show 30V to have noticeably better wear resistance even at a lower hardness. I don't know that CPM D2 will-- or is-- being discontinued due to competition with 30V. I think it is more of a lower demand and maybe some problems with the actual manufacture on the CPM version. Some grades just lend them selves better to the CPM process. Phil
- Joined
- Jan 4, 1999
- Messages
- 3,000
Yes, thank you. I meant SKD. Senior moment.
- Joined
- Apr 10, 2000
- Messages
- 3,794
hardheart, I don't mean it as an argument, when I was collecting steel data and names I ended up with 2 different records for SK5 and AISI 1080 and compositions are pretty similar - 1080 vs. SK5 composition comparison
As you can see not one standard( or alternate name) matches for those two. If you have the source for your data could you plz share and I'll get the chart corrected...
I'm new to posting on this forum (it took me awhile to get the hang of the web thing) but I have been viewing it for some time now. D2 for kitchen knives is a decent choice but if you want to remain somewhat traditional to the Japanese style I would strongly suggest using DC53. It is a great steel. Daido Steel in Japan is the only one that produces it. In the USA I get mine from Lindquist Steel.
The steel is an improved 8% chrome (D2) but the major difference from D2 or SKD11 is that Daido refines the carbides much further. It is basically as close to a powdered metal in terms of grain structure as you can get without actually being a pm steel. It is also half the price of pm steel. I have found that it grinds 70% faster and easier than D2.
The steel is an improved 8% chrome (D2) but the major difference from D2 or SKD11 is that Daido refines the carbides much further. It is basically as close to a powdered metal in terms of grain structure as you can get without actually being a pm steel. It is also half the price of pm steel. I have found that it grinds 70% faster and easier than D2.
- Joined
- Jul 9, 1999
- Messages
- 3,316
Fascinating first post, outrage.:thumbup:
Have any pics of your work?
Also, have you done any head-to-head testing of D-2 and DC53?
That DC53 sounds like a great steel.
Thanks. I will try to get some pictures of the DC53 blades I have. I use to use D2 a lot until I discovered DC53. I friend of mine makes commercial shredder and granulator blades for recycling machines turned me on to it. I find that it is easier to work with vs D2 and heat treats more consistently. You can also get it harder than D2 without sacrificing its shock resistance. I really like the way that it sharpens up. A friend of mine in north Vermont made some small skinning knives from DC53 (he use to use A2) and claims that he will never use anything else. His knife is what worth a picture. Its is sweetest design I've ever seen. Its to bad that it would cost a fortune to produce he is really on to something.