fitzo
Gold Member
- Joined
- Aug 14, 2001
- Messages
- 6,648
The original thread on this particular dagger in question started with a design requirement that it be capable of being "pounded into a tree". That would obviously require toughness. I commented that perhaps one would want to avoid cryo in order to keep a little retained austenite (RA) to favor this characteristic. Steve Hayden has posted a link to a journal publication several times discussing a loss of toughness in A2 after cryo. That is the paper Petah mentions me citing. My thinking was that, since a dagger is primarily a stabbing device, maximizing wear resistance wasn't the critical concern. Petah subsequently said that he didn't really intend to pound his knife into a tree after all, which made my point moot.
While I agree that cryo will increase wear resistance on many steels by reaching their sub-zero Mf, I don't necessarily feel it is mandatory, or even desirable, for every knife. Surely, a blade destined for minimal impact that favors RA will be benefitted by cryo. That said, is it always appropriate to cryo a chopper, throwing knife, or perhaps even a thrusting weapon? Or, instead, can retained austenite be utilized to specifically improve toughness? D2 was originally formulated specifically to have RA in order to improve the toughness of the steel for use in dies, to reduce edge chipping. The secondary hardening characteristics of many high-alloys allow for intentional manipulation of the RA.
I personally feel that we can utilize this situational decision making in the knifemaking process. (And, just for the record, I have been doing deep cryo on knives for many years. So, I don't have any opposition to the technique.)
While I agree that cryo will increase wear resistance on many steels by reaching their sub-zero Mf, I don't necessarily feel it is mandatory, or even desirable, for every knife. Surely, a blade destined for minimal impact that favors RA will be benefitted by cryo. That said, is it always appropriate to cryo a chopper, throwing knife, or perhaps even a thrusting weapon? Or, instead, can retained austenite be utilized to specifically improve toughness? D2 was originally formulated specifically to have RA in order to improve the toughness of the steel for use in dies, to reduce edge chipping. The secondary hardening characteristics of many high-alloys allow for intentional manipulation of the RA.
I personally feel that we can utilize this situational decision making in the knifemaking process. (And, just for the record, I have been doing deep cryo on knives for many years. So, I don't have any opposition to the technique.)
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