Pm steel structure and forging.

Willie71

Willie71

Warren J. Krywko
Joined
Feb 23, 2013
Messages
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I have a question for those of you who know a lot more than me. I have some odd size drops of 3v and z-wear that are thick enough to forge into useable pieces, but would otherwise be scrap. Would forging ruin the advantage of the pm steel or could the grain structure be restored with proper annealing?

Additionally, I’m off most of this week and will be working on my Press. I plan to try mak8ng san Mai with z-wear and cru-wear. What would you guys recommend for the cladding? I have a lot of 304 and 316, and a bit of 410 and 416. Of course I have mild steel, and some 1045 or 1050 too.
 
I talked with someone from either Crucible or B-U about forging and even forge welding PM steel. IIRC, the guy said that forging would not get hot enough to mess it up. Don't remember if he said anything about forged welding as that is essentially how they make the steel to begin with. I think that Hoss has made something with PM steel. Plus if you are just doing san mai, you may not be abusing the stuff for long enough for it to break down.
Willie71 said:
I have a question for those of you who know a lot more than me. I have some odd size drops of 3v and z-wear that are thick enough to forge into useable pieces, but would otherwise be scrap. Would forging ruin the advantage of the pm steel or could the grain structure be restored with proper annealing?

Additionally, I’m off most of this week and will be working on my Press. I plan to try mak8ng san Mai with z-wear and cru-wear. What would you guys recommend for the cladding? I have a lot of 304 and 316, and a bit of 410 and 416. Of course I have mild steel, and some 1045 or 1050 too.
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jdm61 said:
I talked with someone from either Crucible or B-U about forging and even forge welding PM steel. IIRC, the guy said that forging would not get hot enough to mess it up. Don't remember if he said anything about forged welding as that is essentially how they make the steel to begin with. I think that Hoss has made something with PM steel. Plus if you are just doing san mai, you may not be abusing the stuff for long enough for it to break down.
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I was thinking of using 300 series stainless Damascus as cladding once I get some practise under my belt. I think it was Salem, or Nathan that mentioned the vanadium does a very good job of pinning the grain boundaries.
 
Warren, I have an observation and a question. The observation is doesn't it look like Cru Wear austenizes at the same temps as 3V which means that it also austenizes at around the same temps as AEB-L?;) The question is can you do a low temp temper on Cru Wear? :D
 
After the gas atomized powder is produced they create an ingot through the HIP process. After that it is forged/rolled down to thickness through normal methods. You are no more likely to “ruin” it than any other high alloy tool steel.
 
jdm61 said:
Warren, I have an observation and a question. The observation is doesn't it look like Cru Wear austenizes at the same temps as 3V which means that it also austenizes at around the same temps as AEB-L?;) The question is can you do a low temp temper on Cru Wear? :D
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When I do cryo as part of quench, and low temper, cru-wear needs 25f higher austenitizing temp to get the same hardness as z-wear. 1950f, cryo, 400f temper 2hx4= Rc63/64 in z-wear. I need 1975 with cru-wear to get Rc63/64.

I can’t remember if I posted Cru-wear results along with the z-wear results, but my process and experiments are outlined here:

https://www.bladeforums.com/threads/zapp-z-wear-experience-and-heat-treat.1439207/

Aeb-l is a strong candidate for fully hardened z-wear/cru-wear san mai. I only have 1/16” Aeb-l right now, but that is simple enough to fix. :cool:

I sent a roughly finished z-wear blade for Chuck (AKS) to try with the low temper method. He told me the knife was in use in his shop and shipping department for a few months before it started to drag while shaving. I get incredible fine edge stability with cryo/low temper with z-wear/cru-wear. Cutting cardboard and packaging supplies for a couple months with 0.005” behind the edge is pretty damned good imho.
 
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So what would a 1975/400F recipe give you with AEB-L? Approaching 60Rc?
Willie71 said:
When I do cryo as part of quench, and low temper, cru-wear needs 25f higher austenitizing temp to get the same hardness as z-wear. 1950f, cryo, 400f temper 2hx4= Rc63/64 in z-wear. I need 1975 with cru-wear to get Rc63/64.

I can’t remember if I posted Cru-wear results along with the z-wear results, but my process and experiments are outlined here:

https://www.bladeforums.com/threads/zapp-z-wear-experience-and-heat-treat.1439207/

Aeb-l is a strong candidate for fully hardened z-wear/cru-wear san mai. I only have 1/16” Aeb-l right now, but that is simple enough to fix. :cool:

I sent a roughly finished z-wear blade for Chuck (AKS) to try with the low temper method. He told me the knife was in use in his shop and shipping department for a few months before it started to drag while shaving. I get incredible fine edge stability with cryo/low temper with z-wear/cru-wear. Cutting cardboard and packaging supplies for a couple months with 0.005” behind the edge is pretty damned good imho.
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jdm61 said:
So what would a 1975/400F recipe give you with AEB-L? Approaching 60Rc?
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The chart on the AKS site is accurate to what I get in my shop. I’ve never tempered above 350f myself, but according to the chart, it should be about Rc60.

1975, cryo, 400f temper would likely give you an edge at Rc64/65, and a cladding at Rc60. 1950 would likely be core of Rc63/64, cladding at Rc58/59.
 
Looking at the charts, it looks like that Cru Wear would still have toughness similar to that of D2 o maybe a hair better even at 63-64Rc. The chart says that it is half again as tough at 62Rc, between D2 and A2, at 60Rc.
Willie71 said:
The chart on the AKS site is accurate to what I get in my shop. I’ve never tempered above 350f myself, but according to the chart, it should be about Rc60.

1975, cryo, 400f temper would likely give you an edge at Rc64/65, and a cladding at Rc60. 1950 would likely be core of Rc63/64, cladding at Rc58/59.
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Z-Wear performs like improved A2/D2 in my opinion. AEB-L would be a great choice, but how well does it resist etch? Isn't that what turns black in Devin's stainless damascus?
 
Well, then you might ask what color does Cru Wear or Z Wear etch? Does it matter which part is dark if you have contrast?
kuraki said:
Z-Wear performs like improved A2/D2 in my opinion. AEB-L would be a great choice, but how well does it resist etch? Isn't that what turns black in Devin's stainless damascus?
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No, it doesn't I'm just curious. I've etched Z-Wear and it doesn't get black. Only dark grey, almost like zinc phosphate parkerizing. I've not etched 3V but I did try to parkerize it once and it didn't take.

It seems to have something more to do with the alloy than simply chromium, if AEB-L does turn black. That's the reason I'm asking is it's hard to predict. I guess I'll test etch some hardened AEB-L tomorrow and see as this kind of san mai is something I've been very interested in doing for a while.

Here's an owner's pic of the little Z-Wear "thumbsplitter" I made him and etched for about 4 hours.

lotsoftinycuts_zpshrtyfep2-396592.JPG
 
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With a mix like this, we are probably shading more towards the performance end of the spectrum than the looks end. The trick would be to get some kind of contrast that you could shine up kinda purty. :D
 
I want both. I think we can have both. 410 seems to resist etch just fine and stay white. 420 hardens in the same temperature ranges. Maybe I'm wrong about AEB-L turning black or it's being turned black with a different etchant like hydrochloric acid and it resists FE just dandy.
 
jdm61 said:
Looking at the charts, it looks like that Cru Wear would still have toughness similar to that of D2 o maybe a hair better even at 63-64Rc. The chart says that it is half again as tough at 62Rc, between D2 and A2, at 60Rc.
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Toughness is relative. Z-wear at Rc62+ is better than 3v at Rc62+. Z-wear would be as tough at Rc63 as D2 at Rc60. 3v is tougher by far below Rc60. That’s where the better wear resistance and toughness for z-wear claims come in. I’ve settled on a 1935f austenitite for people I don’t know well, and worry about abuse. I get Rc62/63, closer to Rc63, and it’s super tough at that hardness. Wear resistance is pretty damned incredible too.

What I can say is that z-wear is tougher than I would ever need at Rc63. I have done about 20 hunters and skinners at Rc63 or more and none havE come back damaged. I do edges averaging 0.005” which I would never do with tool steels. I’m assuming stainless or high nickel austentitic stainless will give a reasonable contrast.
 
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kuraki said:
No, it doesn't I'm just curious. I've etched Z-Wear and it doesn't get black. Only dark grey, almost like zinc phosphate parkerizing. I've not etched 3V but I did try to parkerize it once and it didn't take.

It seems to have something more to do with the alloy than simply chromium, if AEB-L does turn black. That's the reason I'm asking is it's hard to predict. I guess I'll test etch some hardened AEB-L tomorrow and see as this kind of san mai is something I've been very interested in doing for a while.

Here's an owner's pic of the little Z-Wear "thumbsplitter" I made him and etched for about 4 hours.

View attachment 819269
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This is the point of this thread. I’m going to experiment as the data is quite limited. Of course I’ll post my results as I experiment.
 
I looked at Devin’s site. The high contrast Damascus is aeb-l and 304. Comparatively, aeb-l has higher carbon and 304 has way higher nickel. Aeb-l would etch darker comparatively to 304. Contrast is based on carbon and Nickel for the most part. Chromium and other elements play a smaller role.
 
410 only has .5% nickel, and resists almost as well as 304.

YP7wXgJ.jpg
 
Manganese, eh? Hoser :p
Willie71 said:
I looked at Devin’s site. The high contrast Damascus is aeb-l and 304. Comparatively, aeb-l has higher carbon and 304 has way higher nickel. Aeb-l would etch darker comparatively to 304. Contrast is based on carbon and Nickel for the most part. Chromium and other elements play a smaller role.
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