Aldo 1/8 Thick W2 Not Hardening

Fred.Rowe said:
Just a thought, are you putting the blades into a cold kiln and heating, or is the kiln taken to temperature and then the blades inserted? Eighth inch stock is easy to overheat if its done this way.

Fred
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Ramped up to 1250, stabilized for 10 minutes then put in. Thanks everyone so far. I'll update after this high temp normalize step thrown in the mix.
 
Post your results. I'm doing as you posted above with a controlled ramp up. to 1475.

Fred
 
This time I got 48. Threw in 5 minute soak @ 1650, 5 minute soak @ 1550, 5 minute soak at 1475 then quenched in parks 50
 
May be a dumb question, but are you sure you ground through ALL of the decarb? I wonder if it is from that bad batch he had, however when I brought up the issue of his "bad batch" on face book (in Aldo's knifemakers group), I got one reply by sombody saying that it had been discussed already and that a high normalizing heat could fix it, as already mentioned, however I'm not 100% sure if they were talkin about his W2 in general, or the stuff from the bad batch.. I didn't wanna keep askin cause it sounded as if it had been discussed ad -nauseam there already... I still don't know what was "bad" about tha batch, but that just may be what ya have?? Anyway, I hope you get it figured out, cause I'm interested in what's up as well, I still have by length on 1/8 W2 from his bad batch and wanna do something with it! ;)

~Paul
My YT Channel Lsubslimed
 
Definitely ground through all the decarb and definitely cooling to black.

I re-profiled one of the knives but used 52100 and did it alongside this W2 knife. It hardened fine, just like normal.
 
That's fun....i was just suggesting you to do this tandem testing.
Now we know the tc it's reading fine...
...next i would try a coupon, a big grain growing long normalization with directly brine quenching.
 
Shaw Blades said:
Definitely ground through all the decarb and definitely cooling to black.

I re-profiled one of the knives but used 52100 and did it alongside this W2 knife. It hardened fine, just like normal.
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Then it sure looks like the problem is the steel. I'd contact Aldo.
 
Yesterday I ht 2 W2 blades (bought from Aldo around May 2014 too) - hardened as targeted to 64-65rc AQ. Last year, I posted a thread complained about this batch of W2 - a slightly diff problem. I was wrong:o I hope Aldo keeps the current W2 composition - zero Mo and low Cr&Mn. My ht is not std, perhaps this mod-ht would yield 64+rc for your blades

1. Protect blades with ss foil or clay. Normalize 1750F 20 minutes. Air cool to black; (if clay coated: dunk in water, sand clean)

2. Thermal cycle 5 minutes soak each: 1550F -> 1500F / air cool to black

3. Aust any temp between 1450F -1475F soak 5-7 minutes

a. Rapid slice (agitate) spine first through room temp (~75F) brine for 2 seconds.
Must remove thermal fast enough - due to zero Mo and low Cr&Mn, the pearlite nose is narrow and recalescence heat pump(amplify from fine grain interface). Once pass through PN, go to slower quenchant to avoid dimensional distortion/crack.
​

b. Slow slice spine first through room temp canola oil for 10-15 seconds

c. Wash/clean with soapy water

d. Grind decarb off; hardness test​

Aust steps above will put probably 0.65-0.8%C into solution, while the rest mostly locked in cementite. Putting more C into solution, you might get full hardness with P50 but could result in sub-optimal microstructure (over saturated with C, hence higher dislocation) and possible some grain boundary carbide precip (lowering impact toughness).

Shaw Blades said:
This time I got 48. Threw in 5 minute soak @ 1650, 5 minute soak @ 1550, 5 minute soak at 1475 then quenched in parks 50
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Don - What's Carbon% & others% in your W2? The 2 small pieces you sent me either have higher Carbon% than Aldo(0.934%C) current batch or a little bit deeper hardening.
 
Shaw Blades said:
Definitely ground through all the decarb and definitely cooling to black.

I re-profiled one of the knives but used 52100 and did it alongside this W2 knife. It hardened fine, just like normal.
Click to expand...


Do you want to send me a 1" coupon and I'll test it against the stock I have? PM me and I'll give you my address. (for the sake of testing and seeing what happens. :))

I agree with Don, call Aldo.
 
I'm not casting any shadow on you, only giving a hint about how things can be in MY shop when I say- It's not inconcieveable that a person could grab a piece of steel off the wrong pile, or that the wrong steel could be in the right pile.
So many times when I was ready to go off the handle at a vendor or supplier, I've reluctantly accepted that my problem was due to "operator error."
Hope you find the solution soon, that sounds incredibly frustrating...time to do something cool with a different steel and come back to the W2 later perhaps?
 
bluntcut said:
Don - What's Carbon% & others% in your W2? The 2 small pieces you sent me either have higher Carbon% than Aldo(0.934%C) current batch or a little bit deeper hardening.
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Russ Andrews had a piece from the same batch tested, specs below. The numbers I got from the mill were close to the same, except carbon at 1%. I tend to believe Russ' numbers because he actually sent off a sample for testing.

C .95,
Mn .22,
V .19,
Cr .15,
Si .23,
Mo .013,
Ni .08,
Cu .14
 
elementfe said:
I'm not casting any shadow on you, only giving a hint about how things can be in MY shop when I say- It's not inconcieveable that a person could grab a piece of steel off the wrong pile, or that the wrong steel could be in the right pile.
So many times when I was ready to go off the handle at a vendor or supplier, I've reluctantly accepted that my problem was due to "operator error."
Hope you find the solution soon, that sounds incredibly frustrating...time to do something cool with a different steel and come back to the W2 later perhaps?
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Not really that big of a deal. These particular knives do have a deadline, for a young man's birthday but I've given myself enough wiggle room on time. Glad I have my hardness tester for sure.

Thanks for everyone's help.
 
Thanks Don!

Well, correction to my prev post - Aldo W2 does contained Mo.

Don's vs Aldo's W2 composition
C .95 | .934
Mn .22 | .233
V .19 | .166
Cr .15 | .077
Si .23 | .211
Mo .013 | .012
Ni .08 | .065
Cu .14 | .029
P ? | .011
S ? | .003
W ? | .003
Sn ? | .004
Al ? | .010

Aldo W2 is 98% spheroidized. Exactly why, I recommended 1750F normalizing temperature for 20minutes, projecting 80% cementite will be dissolved and transform/break-up remain coarse cementite into finer shape.

Don Hanson III said:
Russ Andrews had a piece from the same batch tested, specs below. The numbers I got from the mill were close to the same, except carbon at 1%. I tend to believe Russ' numbers because he actually sent off a sample for testing.

C .95,
Mn .22,
V .19,
Cr .15,
Si .23,
Mo .013,
Ni .08,
Cu .14
Click to expand...
 
Don, did you ever see any mill specs on the square stuff?
Don Hanson III said:
Russ Andrews had a piece from the same batch tested, specs below. The numbers I got from the mill were close to the same, except carbon at 1%. I tend to believe Russ' numbers because he actually sent off a sample for testing.

C .95,
Mn .22,
V .19,
Cr .15,
Si .23,
Mo .013,
Ni .08,
Cu .14
Click to expand...
 
Makes sense, Blunt. I forge all my W2 stock down from large stock (starting at around 2000f), then normalize. No spheroidized anneal here.

Joe, no never had any specs on the square stock. It was older and was random drops from large orders.
 
I still have all of that stuff except for the piece that I sent to Mr. Fisk for that first cancer benefit knife.
Don Hanson III said:
Makes sense, Blunt. I forge all my W2 stock down from large stock (starting at around 2000f), then normalize. No spheroidized anneal here.

Joe, no never had any specs on the square stock. It was older and was random drops from large orders.
Click to expand...
 
Russ, the stuff that i got from Don is in a multitude of sizes, all marked by weight. IIRC, it ranged in size from maybe 1.25 or 1.5 square up to like 1.75 x 2.5 and even couple of flat plates that were like 3/4 x 2.5. I sent one of those to Mr. Fisk for the Cancer knife. Like he said that are sawed drops. couldnt' tell you how much I have in total but suffice to say that i keep it in one of those plastic post office bins and it hurts all of my joints when I slide it out form under my bench to clean, so I am guessing maybe 100 lbs minimum. :eek: I bought at least a couple of hundred pounds of the round bar too, so I have been using that for the past 7 or 8 years, but I am getting thin in the larger sizes and the 3/4 and 7/8 are the only ones that I still have a lot of.
Russ Andrews said:
Joe.....are you referring to the 1" X 1 1/2 " W2...?
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