Thread: Liq. N2...so what if I.....?

Ed Fowler did a few experiments with LN on carbon steel (particularly 52100, which is about the only steel he works with), and his tests indicated improvement. Now, 52100, because of its higher alloy content, may be classified more as bearing steel, or non-stainless tool steel, so I guess I'm reinforcing your point. I believe in his experiment, though, he LN treated a tempered blade, then re-tempered after LN, and noted a marked improvement in both ease of sharpening and flexibility. Ed typically uses a triple quench, triple temper process, and gets more out of 52100 than anyone else I can think of. He has perfected his ht process for the way he makes knives. I would assume a maker using 52100 for razors could duplicate his results.

I have no problem with 52100 except that she is a fickle mistress. If you're not paying attention, that steel can and will get away from you and turn a good knife into a piece of junk as the price for inattention.

I'm pretty simple. If the knife improves as a result of LN, then retained austenite is being converted to martensite. That could mean a bad heat treatment regimen up front (carbon steels) or the steel does require that help (high alloy). Some of the new CPM alloys will have up to 25% retained austenite no matter how you treat them even with LN.

I know some factory tool and die guys (69 yrs experience together) who could argue the economy of LN treatments too. They know sharpening the high alloy steel tools really well and their comments are that for the most part it costs more money and does not produce enough improvement in the tooling performance to justify the cost.

What I can't abide is makers rushing like lemmings after a process to make their blades better when it may not make practical sense and old methods work just fine. As long as it's done right in the end I wont' have much to say. And, folks can really do whatever they want to blades whether I have an opinion or not.