Normally when one finds strong positions on topics such as this I may be in the center of it, but I am going to take a more moderate position on this one. It seems no matter what one says in this business, it will be misinterpreted to some degree or distilled down to black or white.
C_Claycomb, I can see where you are coming from since it would appear the every method has at least one Achilles heal.
I would say that any method of heating can do the job for you, after all the steel doesn't know what provides the heat, just some methods have drawbacks and rely more and more upon the faulty human factor.
As I have repeated so many times in the past, it is really just a matter of matching your steel to your equipment. The more basic your equipment the more basic your steel needs to be. One can work under a shade tree on a 1955 Chevy, but one needs much more sophisticated equipment to work on a top of the line 2007 designed for racing.
The fewer tools you have the less alloying you want in the steel. The old blacksmith banged out tools and hardened in nothing but a forge and a slack tub, but his steel was nothing much more than iron and carbon. If we want to work with those tools today we need to find alloys that are still around that could be suited for it. If all one has is a torch, which is even more limited than a coal forge in heating area and atmosphere control, then one will get better results with simpler steels. The simplest we have today are the 10XX series, and of these 1080 or 1084 will yield the best results with the least amount of effort. If you get a 1084 blade up to nonmagnetic with a torch and then quench it, you may actually get enough carbon into solution to be very happy with it. If you move up to something a bit more complex like 5160 and ignoring the smidge of proeutectoid ferrite, you now have a chemistry that needs to be dealt with since chromium carbides are not simple cementite (iron carbide). Just heating it to nonmagnetic and quenching it will yield less than optimum results because you will not pull into play the needed carbon locked up in those chemical bonds with the chromium, that will require
time at temperature. One way that smiths have found around this with simpler tools is to get some into solution and then quench, locking it in solution, and then reheat it to pull the next portion into solution.
Now things get more complicated (like they weren't already
). If one hangs around below the magnetic point for too long that carbon will come right back out of solution and segregate. This is where a torch could work for you, with a flame that can be as hot as 6000F. it is capable of heating very localized spots incredibly fast, so smaller blades can be brought beyond nonmagnetic quickly enough to get at more carbon without losing the last bit. However without any soaking one will need to go to a much higher temperature to break those richer carbides, so if you are not really on the ball there is a good chance of growing grain and other nasties.
Torches are terrible for oxidizing and decarb, but this is off set by the quick heating and short time at temperature. Kilns are really terrible at oxidizing and decarb but are really great for holding times at temperature so all one has to do is defeat the atmosphere problems and they are there.
One can cycle in a forge, kiln or any heat source for that matter but the most critical factor is evenness of heat, for proper normalizing the heat needs to be even throughout, torches don't this very well at all, kilns can do it but slowly, this is why I prefer a forge for normalizing.
Deweyknives, 52100 is a more complex steel and will offer about a hair less of a challenge than O1 in getting proper solutions. Of course one could go the opposite direction and shoot for segregation as this is very popular among many knifemakers today and seems to be attractive to some collectors; it will cut rope like crazy as that edge quickly gets ragged and starts tearing things out of its way, something that is also very marketable today.
I am going to say it again as I figure through repetition it may begin to stick eventually- O1 is not the best steel for beginners with little equipment. Just because you can quench it in almost anything and skate a file, does not mean that you have tapped the steels true potential in any significant way. Lets look at the extra alloying in this steel- chromium, tungsten, vanadium, all in large enough amounts to hog up a lot of carbon, that is why they need to put at least .9% in there. If one wants to bring even a decent portion of it into play they will need to hold the steel at a proper temperature long enough to do it.
Many, and I mean
many, folks would beg to disagree with me on this, maintaining that their 30 second soak on O1 produce blades that cut very well. I produced those same blades for some time. It was not until I started really looking at what was happening inside that O1 that I realized its true potential, and that I was only tapping a portion of it. One can get results that can rival any simpler steel by heat treating O1 without a soak, but why not just use a simpler steel that is much less expensive and get the same results with less cost and headache. If one then goes on to spend the money on more equipment they will find that O1 is capable of not just rivaling simpler steels but blowing them out of the water when cutting.
. It really does go to show how completely subjective performance and design is in knives
. Two guys can build knives that cannot be more opposite, and there is a market for both... DANG! I LOVE AMERICA!
