W2

How long would one have to soak at subcritical to get that banding in steel that started homogenous? I'm not trying to create it, I just want to know to understand.
 
I've never done it. Will probably depend on alloy and how much carbon is in the steel. They try to avoid banding in industry. I think Ed Fowler was getting some on his 52100.

The w2 showing the banding may be on the high side of the carbon range which would develop banding easier.

I would guess forging and cycling in the 1550' range should do it. Not sure how much forging or cycling though.

Hoss
 
Hoss, I had some banding show up in a W2 bowie VERY early on when I was still using the forge to HT and quenching in "medium fast" 11-13 second Tough Quench oil from Brownells. That is before I got a muffle pipe and a thermocouple.
 
Very interesting, I always thought banding was caused by forging or rolling.

Hoss
 
LOL. No you wouldn't. it was an EARLY model and pretty hideous. I sold it to a guy on British Blades for cheap in early 2007 and he posted a pic of it like 5 or 6 years later in a "big bowie" thread. I was appalled. :eek: It worked fine, but he had been using it as a big stag handled BBQ and wood hacking knife, so that should tell you a lot.
DevinT said:
Would have loved to see that blade.

Hoss
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No, No ! Banding is due to the mechanism of solidification of the molten steel !! Very early in the process ! Taking a look at an ingot after solidification the leaner [ lower amount of alloying elements] mix is on the outside and the mix becomes richer as you go to the center.] This becomes a big problem when working with large sections of tool steel where you have massive carbides !! You of course also have the dentritic structure just like when you start making wootz ! When you roll the steel you break down the dendrites .But the rolling also puts everything into bands. But the variation in composition from point to point creates the bands. in industry , no we don't want them !!
 
mete said:
No, No ! Banding is due to the mechanism of solidification of the molten steel !! Very early in the process ! Taking a look at an ingot after solidification the leaner [ lower amount of alloying elements] mix is on the outside and the mix becomes richer as you go to the center.] This becomes a big problem when working with large sections of tool steel where you have massive carbides !! You of course also have the dentritic structure just like when you start making wootz ! When you roll the steel you break down the dendrites .But the rolling also puts everything into bands. But the variation in composition from point to point creates the bands. in industry , no we don't want them !!
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Interesting Mete. So banding is something different than the wootz like stuff we get from multiple heat cycles?
 
Don Hanson III said:
Interesting Mete. So banding is something different than the wootz like stuff we get from multiple heat cycles?
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I searched a bunch of threads in this last night. My hitachi blue blade with the wootz like patterning isn't banding, but likely carbide segregation. If you zoom in on this picture, you can see the pattern. The owner reports the blade performs exceptionally well, better than the W2 blades he has by a noticeable margin, estimated at 20% better wear resistance, so the performance isn't affected much, if at all. The blade took a super fine edge, easily equivalent of W2 or 52100.

image by Wjkrywko, on Flickr

I thought is was bands of decarb at first, but they etched differently than decarb, and the blade was pretty thick before heat treat. I've never had decarb this deep before, or in a pattern.
 
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Nice blade Warren. We get a fair bit of pattern in most of the blades we forge & thermal cycle, but never any banding like the one blade I posted earlier. Wish I had more steel like it!
 
To me - it looks like a hardening issue due to narrow PN. Clues: 1. Hamon sagged toward edge. 2. Pattern shade & texture are similar to hamon 3. Area of solid pearlite lacked of pattern.

Willie71 said:
I searched a bunch of threads in this last night. My hitachi blue blade with the wootz like patterning isn't banding, but likely carbide segregation. If you zoom in on this picture, you can see the pattern. The owner reports the blade performs exceptionally well, better than the W2 blades he has by a noticeable margin, estimated at 20% better wear resistance, so the performance isn't affected much, if at all. The blade took a super fine edge, easily equivalent of W2 or 52100.

26944044063_3014f51e26_b.jpg
[/url]image by Wjkrywko, on Flickr[/IMG]

I thought is was bands of decarb at first, but they etched differently than decarb, and the blade was pretty thick before heat treat. I've never had decarb this deep before, or in a pattern.
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Willie71 said:
Spot on. This is how I came to use 1460f with Aldo's W2 in my shop. I tested a bunch of coupons, and that is what works for me. Stewart mentioned different outcomes with tempering from Don. I tested my tempering temps, and whether my oven is correct or not, I got the same Rc#'s as Don does with his tempering. If I switch to a different oven, I will test again.

Another thing to consider is the effect of grain refinement on hardenability. The finer the grain for a given steel, the lower the hardenability. Kevin told me he tested 1095 that was so refined it could not harden. Normalize, and it would harden again. Edit: I missed that you commented on this. Whoops.

With W2, the clay shouldn't be more than 1/8" thick. I'll go a bit thicker with 1095, and 10f hotter austentizing. Slight difference make a big difference. Journal your results and keep doing what works.
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Yeah this is interesting. For me 1450 range gives me the best 1095 hamon and W2 has to be 1465 or over just to get decent control and hamon not too low. 1095 if i soak 10 minutes it will fully harden, i soak all honyaki 7 minutes from time i shut oven door to quench (oven is equalized @Temp)

-trey
 
comet_sharp said:
Yeah this is interesting. For me 1450 range gives me the best 1095 hamon and W2 has to be 1465 or over just to get decent control and hamon not too low. 1095 if i soak 10 minutes it will fully harden, i soak all honyaki 7 minutes from time i shut oven door to quench (oven is equalized @Temp)

-trey
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Every time someone asks me my recipe, I tell them they have to test their equipment. Each new smelt of the steel has to be refined too. I’ve got about a year of W2 left, then I’ll start the process over again.

Warren
 
Nice to read that thread again. Somewhat OT but how many of you have polished the blades the proper BY HAND way ?? It can show some very beautiful structure .
 
mete said:
Nice to read that thread again. Somewhat OT but how many of you have polished the blades the proper BY HAND way ?? It can show some very beautiful structure .
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I have brought out 1 hamon through polishing alone. Sanded to 2.5k on Hira and 2k on bevel. Then polished the hamon on the Hira with pumice stone. It was a pain but it was beautiful. Some uchigumori fingerstones would have set it to another level though.
-Trey
 
Willie71 said:
Every time someone asks me my recipe, I tell them they have to test their equipment. Each new smelt of the steel has to be refined too. I’ve got about a year of W2 left, then I’ll start the process over again.

Warren
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Yes, i like Alphas 1095 as they will verify the cert and it is very clean (1%c, .44%Mn and little else) and I'm also using Aldos current batch of W2. Tbh I prefer the 1095 but the W2 sells better. The W2 takes a better hamon and have gotten very good hamons quenching from 1440 to 1460 but after my past 6 hamons dipping very low I am now austentizing around 1460-1480, still some experimenting left to do.
-Trey
 
comet_sharp said:
I have brought out 1 hamon through polishing alone. Sanded to 2.5k on Hira and 2k on bevel. Then polished the hamon on the Hira with pumice stone. It was a pain but it was beautiful. Some uchigumori fingerstones would have set it to another level though.
-Trey
Click to expand...

Pics or it didn’t happen :)
 
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