I thought I'd take the time and catch folks up on the progress, or lack there of, on the "cryo" experiments that I've been a part of.

I've been involved in a series of different treatments, from just plunging a blade into -100F after the quench, then normal tempering, to a series of cold treatments {-100 and -300} and tempering treatments. Some of the custom gun guys swear by the "series" stuff...........

Well, actually, all I noticed with just the plunging into the cold was a funky blue color overlaying the ussual black. Maybe the edge is a bit softer......

Since we've started the "series" stuff, I have noticed a difference. The edge is definitly softer. The "ussual" harden/ quench/ temper route we do generally gives me a 52rc body, and the edges are ussually 3 to 4rc harder than the main body. After the "series" treatment, the whole blade is a bit softer....

We've done this now, enough to start feeling a pattern. If the body of the control blade tests 52.2rc, the body of the blade that went thru the temper- cold - temper -cold - temper routine is ussually 51.8rc. If the edge of the first tests 55rc, the 2nd now tests 52rc.

Oddly enough, it seems that the blade that was sent to Angel Sword did the same thing. Its softer than the "control" blade, though not enough to panic over.........

On the stuff done here locally, there doesn't seem to be an advantage to "flex", nor impact resistance. And the edge holding seems to have lost a bit. Not sure that this is the way I want to go........

There was one test, where the cryo'd blade bent further before taking a set, and held up better before snapping. But the difference was like 5%. And checking the wreckage after the fact, there was .01 inch difference between the two blade's thickness, which may have more to do with the different results than the cryo series...........

Now, this may not mean much as to how much a good cryo series like Angel Sword does, will help the average smith or swordmaking firm. Most folks and heat treating firms do not do things as meticulously as the heat treater I use. There is very little retained austenite in my blades, where you will find a decent amount in most blades made today........ As an aside, I believe that Angel Sword's service could add value to a lot of blades out there.........

Not that there is anything real special about the way my blades are heat treated. The heat treat is actually very basic, just very meticulous. A reasonable quality for the dollar spent........There are smiths out there who do a better job on their favorite steels, fellas like Kevin Cashen and that rascal Howard Clark. But, for every KC or HC out there, there are several who could use some help.......

My very politically incorrect opinion..........

Auld Dawg

Hi Gus,

I thought you sent your stuff "out" for heat treat - are you doing it yourself now?
Interesting results.

Gordon

Hi Gordon

Nothing's changed, I still take stuff down the street to the heat treater........

Maybe I should have clarified in that my stuff has been involved in those treatments, then afterwards I got the blades back to finish and test...........and break........

Was the blue color permanent/all the way through, or was it just an overlay?