W2 Tempering Options

[Carterwhopkins]

Thanks Carterwhopkins , that's the batch I have. What is your HT protocol?

1600f 20 min air cool, then 1475, 1450, 1425 each for 10-15 min and air cool. 1460f 10 min, maybe a tad more for thicker blade 15 min probably longest time, quench in Parks 50. I am tempering at 2x 375f for 2 hours, water quench.

 

[Willie71]

Warren, your info is always appreciated here, so if you have the time, for sure we would love to hear your process!

I’ve got the W2 with .92% carbon. I use normalizing and cycling of 1650, 10 min, cool to black, 1450f x 10 min, cool to black, 1450f x 10 min, cool to black. If I have to grind more, I’ll use 1200f x 2h for a subcritical anneal. Then1460f, 8-10 min, quench in DT-48. I get Rc67 consistently, and the occasional Rc68. I temper at 425f for Rc62/63, and 450f for Rc61/62. I’ve never had a blade break, or an edge roll or chip.

For the lower carbon recent batch, I’ve heard of people using 1475-1500f. I don’t have any from this new batch, so I haven’t tested it. I still have 8’ of 1/4”x2” from that first good batch left. I used all of my 3/16” and 1/8” already. Down to the last bit.

Austenitizing temp is largely based on carbon content since there is no real alloying in this steel. Do coupons in 10f increments and find the highest as quenched hardness, then temper as needed. I found going more than 10f higher or lower than optimum created less consistency in hardness, and going more than 20f from optimum decreases overall hardness. There is a tight window to get it right.

I had a thread on this with my numbers listed, but it didn’t show up in a quick search. Edit: here’s some of the numbers. I seem to remember listing all 10 readings for each coupon somewhere, but can’t find it. https://www.bladeforums.com/threads/52100-vs-w2.1188438/page-4

 

[jdm61]

I have been able to snap a very thin santoku blade that was tempered at 375F. But it did break very cleanly.

 

[samuraistuart]

Warren, I also don’t have ( or plan to use) the most recent batch of W2. Carbon content too low for what I want. And I am now out of W2. Shame. But I do have a short bar of the early early 1/4” W2. What to do with it tho. If I want Hamon it’s 1095 for me from now on. Until we can get some higher carbon, and better quality, W2 back.

My process is almost identical. 1650f for 20 minutes to normalize. 1475f x 2 air cool. 1425f air cool. 1460f 10 minutes Parks 50 quench. 400f 2x 2 hours each for ~63HRC.

I was blown away when I saw the chem comp of the recent W2. .73% carbon up to .85% carbon. Too wide of a range, and way too low. Add that to the spheroidizing issues.....meh.

 

[Willie71]

Warren, I also don’t have ( or plan to use) the most recent batch of W2. Carbon content too low for what I want. And I am now out of W2. Shame. But I do have a short bar of the early early 1/4” W2. What to do with it tho. If I want Hamon it’s 1095 for me from now on. Until we can get some higher carbon, and better quality, W2 back.

My process is almost identical. 1650f for 20 minutes to normalize. 1475f x 2 air cool. 1425f air cool. 1460f 10 minutes Parks 50 quench. 400f 2x 2 hours each for ~63HRC.

I was blown away when I saw the chem comp of the recent W2. .73% carbon up to .85% carbon. Too wide of a range, and way too low. Add that to the spheroidizing issues.....meh.

I’m in the same boat. 1095, or Hitachi white. Aldo is in real trouble as far as I can tell. His steel is just not reliable.

The recent W2, I’d you can even call it that, is not what I am willing to sell to my clients. I have never made a 1075, or even 1084 kitchen knife, and this last batch of W2 is in the middle of those two.

 

[Carterwhopkins]

I see you did full thickness unprofiled bars. That will make for a lot of post-HT grinding for Rc 63-64 blades. Hope you have a big dunk bucket and lots of belts ... as well as time.

Clean this batch up, grind the knives, and check the hamon before doing the next ones. No use in repeating the same thing unless you know it got the results you wanted. I would suggest doing the blades two at a time to learn how to place the clay and control the hamon.

BTW, are you saying the hardness was Rc 66-67 in the clayed upper spine area, as well as the lower unclayed area? That doesn't sound like you will have any hamon.

Hi Stacy...missed this yesterday.

The thick bars are my heat shield from the coils, not blades. I am getting good results with the hard edge @67 and soft spine @30's areas and the hamons are ok using Rutland, I have not finished a blade with satanite yet. Here is recent pic of W2 w/ Rutland at @63.

 

[Carterwhopkins]

I did HT on 6 W2 blades this weekend....one gave me some hardness #'s that were wide ranging and much lower than anticipated. I am going to take a coupon off each bar and test....is there any reason to do a piece larger than 1"x2", also do it matter if I take it through the normalizing process or proceed direct to hardening?

 

[Willie71]

I did HT on 6 W2 blades this weekend....one gave me some hardness #'s that were wide ranging and much lower than anticipated. I am going to take a coupon off each bar and test....is there any reason to do a piece larger than 1"x2", also do it matter if I take it through the normalizing process or proceed direct to hardening?

I’d normalize and cycle to make sure steel condition isn’t affecting the results. 1/2”x2” is big enough.

 

[Carterwhopkins]

Thanks Warren.

 

[Willie71]

Thanks Warren.

Keep track of which end you hold with the tongs, as that end won’t harden. I didn’t mark one batch once, and had to redo it. You probably know this, but I’m just being ocd here.

 

[Carterwhopkins]

Of course I remembered that....thanks for reminding me...good info.

 

[Flagg]

I’ve got the W2 with .92% carbon. I use normalizing and cycling of 1650, 10 min, cool to black, 1450f x 10 min, cool to black, 1450f x 10 min, cool to black. If I have to grind more, I’ll use 1200f x 2h for a subcritical anneal. Then1460f, 8-10 min, quench in DT-48. I get Rc67 consistently, and the occasional Rc68. I temper at 425f for Rc62/63, and 450f for Rc61/62. I’ve never had a blade break, or an edge roll or chip.

For the lower carbon recent batch, I’ve heard of people using 1475-1500f. I don’t have any from this new batch, so I haven’t tested it. I still have 8’ of 1/4”x2” from that first good batch left. I used all of my 3/16” and 1/8” already. Down to the last bit.

Austenitizing temp is largely based on carbon content since there is no real alloying in this steel. Do coupons in 10f increments and find the highest as quenched hardness, then temper as needed. I found going more than 10f higher or lower than optimum created less consistency in hardness, and going more than 20f from optimum decreases overall hardness. There is a tight window to get it right.

I had a thread on this with my numbers listed, but it didn’t show up in a quick search. Edit: here’s some of the numbers. I seem to remember listing all 10 readings for each coupon somewhere, but can’t find it. https://www.bladeforums.com/threads/52100-vs-w2.1188438/page-4

Is wrapping blade in kitchen foil for any heat treatment advantageous????