- Joined
- Sep 29, 2015
- Messages
- 229
how did you quench these?
I quenched those with the Parks 50 you were kind enough to send me I agitated for 30 seconds and then left them in the oil long enough to cool completely. It was at about 80°F.
The BladeForums.com 2024 Traditional Knife is ready to order! See this thread for details:
https://www.bladeforums.com/threads/bladeforums-2024-traditional-knife.2003187/
Price is $300 $250 ea (shipped within CONUS). If you live outside the US, I will contact you after your order for extra shipping charges.
Order here: https://www.bladeforums.com/help/2024-traditional/ - Order as many as you like, we have plenty.
how did you quench these?
W2(AISI) - Water hardening tool stee
W2(AISI) - Water hardening tool steel. Quite popular with custom knife makers, beginners and seasoned experts alike. Easy to work with, decent edge holding and ok. toughness, depending on the heat treatment. Maximum working hardness is in 63-65 HRC Range. Obviously, you won't be getting much of the toughness at 65hrc, however edge holding and cutting performance for thin edges increase accordingly.
W2 a is just as bad(read, broad) in terms of specification precision as AISI W1 steel. Carbon varies from 0.85%-1.50%. Huge variation for an alloy. Trace amount of Chromium serves primarily as a carbide former, may be adds something to alloy strength as well, but nothing in terms of stain resistance, too little of it(Cr). W2 maxes out 64-65HRC when enough Carbon is present, and works quite well at that hardness levels as a light use knife. Pretty good with polished, thin edge at 64HRC. I've seen various types of knives in all sizes, starting from small folders and ending with rather large kitchen and utility knives. Overall, it's a decent steel, non-stainless, won't win any awards in abrasive wear resistance department, but will do variety of jobs.
Why you not try to quench it in the water ?
I quenched those with the Parks 50 you were kind enough to send me I agitated for 30 seconds and then left them in the oil long enough to cool completely. It was at about 80°F.
Re hardening W2 can decrease hardenability, as the grain gets finer every time you go through the phase transformation.
Secondly, there are a few bad bars of W2 out there. Sometimes that is the issue.
Third, this is why I always normalize and use grain refining cycles. The steel is in the same condition, every time I heat treat.
If I get a new supply, I test a piece before I make a knife to verify my heat treat is consistent with that batch. I'm down to the last few bars I bought from Aldo with his first good batch a few years ago, the batch those posts you referenced where I did my testing.
Fourth, is there possibly an issue with the thermocouple, reading inconsistently? I know you tested it, but if there is an intermittent problem.
Hamon are a rabbit hole, as you are finding out. When you get a supply you like, buy a lot of it. Saves some headaches.
Hey Jeff, it sounds like you are changing more than one variable with each iteration. That would make it hard to nail down the culprit, and could be part of your problem. I'm not much of a knife maker, but I a guilty of the same thing!
Sent from my iPhone using Tapatalk
I was just curious if you had used brine or the oil for those numbers. Thanks for the further data!
Also, Jeff, the oil I sent you is the same as the oil you've purchased if you purchased it through Maxim. My 5 gallon jug only says "50 quench oil" or whatever. Not Parks 50.
I'm willing to bet you either have a furnace/thermocouple fluctuation or a bar of W2 that is inconsistent. I think you should put away the notebook and make a knife. You know what temp you need to hit 66 RC. You know your quench medium is correct. I think further experimentation is going to have you chasing your tail.
Use the satanite clay for your normalizing cycles. Get rid of it for your austentizing cycle, as the amount of scale you're going to develop in a single 10 minute soak is pretty minimal.
I appreciate the input Willie so thanks for trying to help.
As far as re-hardening decreasing hardenability most of my tests have been done with new steel so that isnt really a factor in this case. But I am starting to suspect that perhaps I do have a bad bar of W-2. The bar I have been testing I bought from Canadian knife supply in Alberta who told me it was from the steel baron but since then I have bought 3-4 foot pieces 2 x 3/16 directly from The Steel Baron.
I am thinking I will do a test with the new steel I bought directly from The Steel Baron and see if that makes a difference. Maybe I do you just have a bad bar because it is really weird that I get good results one time and using the exact same procedure and equipment I get dismal results.
And I do understand how normalizing may help this so maybe in the future I will start normalizing all my W-2 but I havent been because I did try it once with this bar and it didnt make any difference in hardness. But yes that may be wise in the future.
And thats what I thought that it probably was my thermocouple but I have an external one also and I used it to check against my one that is part of my oven and they seemed to be about the same in comparison to each other as they were before so I really doubt it is a temperature issue.
And yes you are correct sir a hamon certainly can turn into a rabbit hole and I would just switch steels and because I found 1095 much easier to heat treat with more consistent results I would just switch to that because from what I have read it gives a Hamon almost as good as W-2 but the problem is I now have 12 feet of W-2 and I would hate it to just go to waste.
So I am going to try and test some of the new W-2 I have directly from Aldo and see if thats the issue and I think I will quench in parks 50 and brine to see if they both harden the same. I was a little disheartened yesterday but there has to be an answer because if I am getting good hardnesses sometimes eventually I should be able to figure out how to get it all the time. Hopefully it is just that I have a bad bar. I was thinking of doing some hardness tests on the bar before heat treating because I would think it should be pretty consistent even in the annealed state? Maybe that would be an indication if it is a bad bar?
Regarding the normalizing: some of Aldo's stock is highly course spheroidized, and won't harden, even with a 30 minute soak. It's worth normalizing, cycling, and then hardening to rule this out. If the steel hardens, but doesn't get full hardness, this may be the issue too. Before deciding a bar is bad, mormalize and cycle a coupon, then heat treat. Over cycling the steel may put it past the point where even parks 50 would get you last tne pearlite nose. This is when I try brine. If it hardens in brine, then it might be best to normalize, and do one fewer cycles refining the grain. As you have found out, W2 is very picky, and there are at least four batches, maybe 5 out there, and there is inconsistency in the structure between the batches. There are bars that simply won't harden, no matter what you do.
I'm not looking forward to restocking W2 with the inconsistency in supply. Even getting two thicknesses from the same supplier could be different batches.
Edit: do you want to send me a piece of your bad steel for me to try with my setup? If I get the same results as you, that would confirm it's the steel, not anything else. I'm getting pretty damn consistent results with my supply. I'll pm you my address if you want me to try.
The sequence I use is 1650 for 10min, cool to black (magnetic), 1550f for 10 min, cool to black, 1450f for 10min, cool to black and quench. 1350 or 1200 will stress relieve and fine spheroidize the steel. The first cycle it above ac3, which grows the grain, making it all the same size, and its hot enough to break up the course spheroidized carbides. The two subsequent heats result in new grains forming within the old grain boundaries. The heat is low enough that the grains don't grow. I'm not sure about the reason for the quench on the last cycle, but those with mire knowledge than me said it can lock everything in where we want it, so I trust them. The subcritical temps are only needed if one has to grind or machine the steel, as spheroidized structures machine easier than pearlite.
Ive given up on the w2 bars I have. I've have over a hundred test samples with nothing consistent. I've got pages and pages of notes. I've gotten the exact same results as you. Same process same temps one day is 44 the next day hard as woodpecker lips. I'm behind on orders because of my inability to leave this steel alone. Ive had it tested, and I've emailed back an forth with numerous folks to try different things.
You have an email I can reach you at?
To send an email to any member just right click on their name on any of their posts and then click the send email icon.
Tried that with yours before I posted. It's not an option on yours, that I an find