HT'ing info for CruForgeV
That is why they added the vanadium....to keep grain size down, especially if temp control isn't as good as it should be. Going through a thermal cycle(s) to reduce grain size won't be totally blown away by austentizing at 1550. The vanadium being a great aid in keeping grain size small. Take any steel that you want to reduce grain size.....usually that last heat during thermal cycling/normalizing is way below austentizing temps, but we don't negate all that work when we go to harden. And it is to my understanding that what we are doing is actually creating more nucleation sites every thermal cycle so that more grains form there. And again, I'm just trying to learn this stuff. I am no expert.
If it were a simple 1095 steel, I would absolutely say to harden no higher than 1500...and is best at 1475 or below. There are basically no alloying elements. However, with 52100 or CFV there are alloys added to the steel to aid in hardening, grain size, edge retention, etc....and to get the carbon and those alloys into solution and distributed evenly, we go through those normalizing steps. My question that I guess I'm just going to have to test myself, is why such a huge (50 to 75 degrees) allowance in aust temperatures on these alloy steels? If everything has been set up properly during thermal cycling, do we use the higher or lower temps? I just don't know enough to answer that myself.
I'm sorry, but I'm at a loss as to what you mean by "how about doing more grinding and sanding before hardening."
When Crucible wanted to make a "high tech" forging steel, they got with several knife makers and asked them their opinions\advice in what was needed to make this steel the best forging steel on the market. From what I've read, I still haven't gotten the big hunk I bought forged down to a reasonable size so I still can't say I have experience with it, but what I read was to do the Thermal Cycles, get it red hot and let it cool to dark, 3X's, after that, the HT is simple, get it red hot and quench it, the temper was basically around 400 degrees 2X's, the statement was made that it was almost impossible to NOT get this steel hardened. That it could be done in a forge easily, with no special equipment needed. That was the goal Crucible was after and from what I've heard it looks to be like it maybe a very good steel for knifemakers.
The difficulty in grinding it, I'm not aware of, but I will soon find out, it is easily possible that you got a bad piece that may have slipped through their Q&A crack..., not likely but anything can happen. I do know that Smelters will have bad batches from time to time, be it from too much left overs in the crucible (the big bucket they melt the steel in, not the company), or other elements that can be absorbed from the air during the smelt.
The first thing I was thinking after reading about it being hard to grind was, " how tough of a knife will this stuff make, if it is hard to grind and it's not hardened yet!"
If this stuff is everything they say it is and can do, it should be an awesome steel for knifemakers, I won't know until I make a knife out of it.
Rex
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JUST EDITED 3/11/14, WITH THE HTing info for CruForgeV
Here is the actual text I was referring to:
"CruForge V was developed specifically for forging into knives. Scott Devanna coordinated with knifemakers when developing the steel. The result is an excellent steel that forges and performs very well.
CruForge V is easy to forge but tougher to finish than any of the 10XX steels or 52100. The tradeoff is edgeholding. The vanadium in CruForge makes it hold an edge longer than the 10XX steels and 52100."
Now with that said, it DEFINITLEY DOES LOOK LIKE IT WILL BE A BEAR TO GRIND and HANDSAND. BUT! The trade off is EDGE- HOLDING!!! So, the thing to do is to take it to as close to finished, if not all the way finished before HTing the blade. And then, of course finishing it, AGAIN! After the blade has been Tempered. Not a major deal to me, as I just about do my knives that way now....I found out a long time ago that the sooner I get it away from the grinder, the better for ME! And I still spend an incredible amount of time hand sanding, almost to the point (and actually to THE point or edge) of sharpening several knives. I just found what was my way, and what I tell all new makers,"The best way for you to make a knife is the best way YOU, can make a knife". What works for others won't work for everyone, for me, I was getting the first few knives I was making a l m o s t done, then a burp here or a bump there and the blade was scrap! So this was the best way for me to remedie the problem and I have had 100% SUCCESS since, it just takes me forever to make a knife!!! I am getting better and since I got The Bubble Jig , my speed has increased as well!
And just for kicks here is the HT info. I tried to copy the chart but it wouldn't copy, I will try again once I can get on a real puter and off this iPad !!!! From what it looked like to me the Temper temp is 425, for a Rc 58-59! From the looks of the chemical break down it say the Maganese is .75 percent. I can't recall if it needs to be below 3% or .3% to get a HAMON!!!! WOW! A Hamon on that steel = a gluten for punishment!!!!! Or just plain dumb, so if it is within the boundaries to get a Hamon, I WILL attempt to...maybe, I might be dumb, but I ain't stupid! That will be really tough to accomplish..but, how cool would it be? And how many would there be???? Not many I'm thinking! And here is the HT info, REX
Heat Treating Information:
Austenitize: Heat to 1500-1550°F and equalize. Quench in oil.
Temper: Double temper at 400-500°F recommended. Approximate hardness after double tempering is shown below. Actual hardness will depend on hardening temperature and quench rate.( the "chart below" it is referring to is the one that I could not get to copy) I'll try again later.
