NJSB W2 ht results

BluntCut MetalWorks

BluntCut MetalWorks

Knifemaker / Craftsman / Service Provider
Joined
Apr 28, 2012
Messages
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Paragon 24D oven
ht (fyi - translated to an equivalent conventional ht thermal processes, since my ht is almost 30 hrs excluded cryo time): normalized 1800F, grain refinement, hardened 1460F 10-12 minutes soak, interrupted super quench, cryo.

W2 purchased April 1st 2019: 3/32" thick, 3 coupons, 1 blade. AQ 67rc ~ 10 hrc readings (66.5-67.5)
W2 bought 2016: 1/8" thick, 3 coupons, 1 blade. AQ 67rc ~ 6 hrc readings

I also ht-ed 52100 from njsb and aks, 1095, 1084, O1, cfv. cfv warped fbar, others were tinkered with minor to major autotempered. At any rate: 1095 66rc, 1084 65rc, O1 66rc, 52100 65rc.
 
Good job on posting the results Luong With consistent results like that we're pretty sure you did the HT correctly - as usual.

BTW, you need to keep your "Catching Shrimp with Bare Hands" link up. This was a very fascinating book and I enjoyed it very much. Thank your wife for writing it.
 
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Heat treat correctly? I would just like to point out a few things:

1. 1800f normalizing temp. That’s 150f-200f hotter than it should be. I am curious as to 1650f normalizing temp.

2. Superquench. This is a faster quench (I’ve heard) than even water or brine. I am curious as to Parks 50.

3. Cryo was used. W2 is not a steel that needs it. I am curious what no cryo would result in.

In other words, what would a 1650f normalizing temp, thermal cycle, 1460f 10 minute soak, p50 quench, no cryo post quench hardness result be? Hence the issue in the first place. I haven’t used any W2 in over 3 years, because VERY well respected makers, who no longer post here, even have had issues with various generations of it...hence the whole subject being brought up, and admitted issues from NJSB about it.

Just because Luong figured out how to get it to harden (just like others have) doesn’t dismiss the whole issue.
 
Ken H> said:
Good job on posting the results Luong With consistent results like that we're pretty sure you did the HT correctly - as usual.

BTW, you need to keep your "Catching Shrimp with Bare Hands" link up. This was a very fascinating book and I enjoyed it very much. Thank your wife for writing it.
Click to expand...

Although the hardness is as expected, I still will look for if any obvious discrepancies in wear resistance (if anything obvious) between 1095, 1084 and these 2 W2. Unless new W2 at 5160/1075 level, I doubt my pulse-check test will able the quantify differences between the 2 W2.

You right, Ken, maybe I should put the link back my signature. The book is available on Amazon and local book store.
Thanks.

samuraistuart said:
Heat treat correctly? I would just like to point out a few things:

1. 1800f normalizing temp. That’s 150f-200f hotter than it should be. I am curious as to 1650f normalizing temp.

2. Superquench. This is a faster quench (I’ve heard) than even water or brine. I am curious as to Parks 50.

3. Cryo was used. W2 is not a steel that needs it. I am curious what no cryo would result in.

In other words, what would a 1650f normalizing temp, thermal cycle, 1460f 10 minute soak, p50 quench, no cryo post quench hardness result be? Hence the issue in the first place. I haven’t used any W2 in over 3 years, because VERY well respected makers, who no longer post here, even have had issues with various generations of it...hence the whole subject being brought up, and admitted issues from NJSB about it.

Just because Luong figured out how to get it to harden (just like others have) doesn’t dismiss the whole issue.
Click to expand...
Maybe you misconstrued Ken's 'correct ht' meaning. I interpreted Ken's statement as - my unconventional ht got good consistent results, thus ht correctly. My post is a follow up in context of the hotly debated & now closed thread about new W2. I prefer to post a follow up than made this new thread...

To be clear - In that closed thread, I stated testing would based on my unconventional ht.

Addressing your points:
1. For almost 2 years now, I've been normalize low alloy carbon steels in 1800-2050F range. I found 1650F take too long to dissolved 95+% of heavy spheroidized njsb carbon steels, 10-30 vs 120 minutes. With good confidence that my result would similar if w2 was normalized at 1650F for 2 hrs. I aware of your+others ht normalize time is 20-30 minutes, which would works poorly for my ht.

2. SQ is indeed very fast ~ 2s vs brine 5s vs p50 7s vs warm canola 10-11s. P50 isn't fast enough for my ht w2; 1095 and sub optimal(sometime with soft spots) for cfv,52100,1084,O1.

3. W/o cryo my hrc would be 1.5-2rc lower than posted. After 24hrs of ht just before cold treatment, w2 hardness readings were right around 65rc.

I will compare grain size of these 2 W2 and 1084. If new W2 has similar grain size as 1084, then I will investigate further.
 
And I just want to say, and this is probably going to be one of my last posts on this forum, that is not how W2 is heat treated. This is the whole point of the whole thing. We know how to HT W2. We know the issues of the recent W2 in the past. We know how to overcome these issues. But just because we’ve figured out how to overcome them doesn’t correct a thing.

And again......(not an attack on Luong/Bluntcut)....just stating the obvious....

1. The temps you have (correctly) found to normalize NJSB carbon steels are WAAAAY too high. Unacceptable. NJSB has apparently addressed this issue and will hopefully have the mill’s annealing process amended.

2. Superquench should NEVER be needed to harden ANY knife steel properly. EVER.

3. Again...your AQ numbers are based upon and absurdly high normalizing temp, and absurdly fast quench, and a cryo quench that W2 of course does not need.

And if anyone has a problem with the issues I bring up, I don’t know what to tell you, except do some simple research on how to HT simple carbon steels. (Not aimed at you Luong)


O1 has more alloying and carbon (at least more carbon than this W2), and you can get O1 from just about anywhere and it’s ready to harden as received. Same with A2. Same with any steel, except the hoops we have to jump thru to get NJSB carbon steels to respond correctly without the whole “normalize” and “cycle” routine....that “may” or “may not” result in correct results.
 
I need thinner W2 for my experiment - R&D_IP batch #3 (added 2 w2 cleaver and 1 52100 bolo)

bgAbBth.jpg


reason why I got some newer thin stock from njsb. So after 1 hardened batch (11 items out of 53), new and old w2 produced same hardness using the same ht - sharing this simple info = the goal of this thread. I didn't make any claim that new w2 stock would work for anyone else ht process. Quite certain, I am not bashing consensus ht method.
 
bluntcut, how are you heat treating your Niolox? How hard can it get?
 
Equivalent to ht as: aust 1950-2000f, 20-30minutes soak, plate or oil quench, cryo, completing mf with 275F 15 minutes soak then dunk in water.

peak hrc: 64-64.5rc when quenched with plate, 65-65.5+rc when quenched with oil.

Here is a fun 36 seconds slow-mo 64+rc niolox chopper (~ 18dps) in action:

cotdt said:
bluntcut, how are you heat treating your Niolox? How hard can it get?
Click to expand...
 
The issue with some steel not hardening was found. Some of the steel from the edge of the roll made it through quality control. The carbon was too low, between 0.75-0.85%, and inconsistent within the bar. NJSB has committed to correcting the problem.
 
I got that - same day you posted in your thread, thanks :thumbsup:. I am sharing (hindsight now) 'hardening fine' w2 has similar composition as the old one. Peter already acknowledged new W2 failed some spot check in carbon% = fact, yup. Also fact, I will be using new W2 for my R&D experiment, since there were no 3/32 old stock and I've a bunch of 1/8 and thicker stocks. I sure don't want to introduce unnecessary steel composition uncertainties into my research. Along the way, if I see odd behavior/result with new w2, I will cease using it (no biggy, I didn't buy a huge amount anyway), won't miss out much, since I already using 52100, cfv, o1 steels for testing anyway.

Willie71 said:
The issue with some steel not hardening was found. Some of the steel from the edge of the roll made it through quality control. The carbon was too low, between 0.75-0.85%, and inconsistent within the bar. NJSB has committed to correcting the problem.
Click to expand...
 
Willie71 said:
The issue with some steel not hardening was found. Some of the steel from the edge of the roll made it through quality control. The carbon was too low, between 0.75-0.85%, and inconsistent within the bar. NJSB has committed to correcting the problem.
Click to expand...

How wide was the roll? How much carbon in the center?

Hoss
 
DevinT said:
How wide was the roll? How much carbon in the center?

Hoss
Click to expand...

Not sure about that, the pieces i had test with the low carbon were only 2 x 4 inch coupons. One of them I was told had .4% V or something which imo sounds more like the reason behind failure to harden. Alloy pooling I guess. Pete said he sent that sample to the mill so they can figure it out.
-Trey
 
DevinT said:
How wide was the roll? How much carbon in the center?

Hoss
Click to expand...

The Center was 0.92% iirc. I don’t have the other info. Maybe Peter from NJSB can clarify. The specs were out for some bars, others tested as normal.

I’ll msg him and ask him to respond.
 
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As a part of this whole ordeal I'm checking my oven for accuracy. It was suggested to melt table salt in my kiln (melting point 1475) as a way of checking this. I've read some conflicting opinions as to whether this is this a good idea.

I also just bought a K type thermocouple and PID from Auber Instruments. Is this a better way to check the accuracy?
 
cotdt said:
You can use thermal paint to check the accuracy of your kiln. It changes color at a specific temperature as marked on the bottle.
Click to expand...


I’ll look into this. I used a second thermocouple twice to verify temps. That assumes the second thermocouple is accurate.
 
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