Cruwear corrosion resistance

[Lancerpt]

Saw the new PM2 in cruwear from knife center. How does corrosion resistance compare to S30v, M4, S110V.....all the other mainstream steels? Hope a PM2 gets released in LC200n!!!

[The Meat man]

Cru-wear is a non-stainless tool steel, unlike S30V and S110V, which are both stainless. Cru-wear can rust/corrode if neglected.

However it has a high chromium content so I've heard it's actually pretty corrosion resistant for a non stainless steel. Certainly better than 1095 or 52100 for example.

[bearfacedkiller]

Much more corrosion resistant than M4. Nowhere near as corrosion resistant as S110V. Despite what the chemical composition says I have found it similar to S30V. I put my Cruwear Military in a glass of white vinegar for two hours and nothing really happened. If it isn’t neglected I find Cruwear plenty corrosion resistant.

[Pelagic]

I put my Cruwear Military in a glass of white vinegar for two hours and nothing really happened.

Wow! Good to know.

[bearfacedkiller]

I think it did get a very, very small bit of grey coloring towards the tip but I could only see it in the right lighting and I have never been able to capture it in a pic. I put a knife made from D2 in at the same time and it turned a dark grey.

I don’t actually like forced patinas and did it just as a test. They have both been Flitzed back to shiny since then.

[Pelagic]

Interesting, iirc d2 has fairly high chromium compared to other non-stainless tool steels.

[The Meat man]

I think it did get a very, very small bit of grey coloring towards the tip but I could only see it in the right lighting and I have never been able to capture it in a pic. I put a knife made from D2 in at the same time and it turned a dark grey.

I don’t actually like forced patinas and did it just as a test. They have both been Flitzed back to shiny since then.

BFK, how would you compare Cru-wear to ZDP-189 for corrosion resistance?

[blueblur]

With my experience it is less resistant than S30V but more resistant than M4. The only time I’ve seen an issue with Cruwear was when I was on a motorcycle trip where I was rained on and off throughout the day. The last part of the day we were poured on for 1.5 hours and when I finally checked out my blade it was soaked and had 2 very small, light rust spots. One on the secondary grind but I was able to “buff” them both out with just a few minutes on my t-shirt. My brothers M4 blade had some heavy patina but was still in worse shape.

I’ve never noticed Cruwear change color or noticed any sign of corrosion on S30V or S110V.

[HarleyXJGuy]

Carried my Cruwear Military for about half of my last Afghanistan deployment and didn't take any special measures to protect it.

Nothing that I can see for discoloration or rust still to this day.

Not very scientific but there you go.

[ZrowsN1s]

I honestly thought it was stainless.

[npad69]

i find it more stainless than the 420HC stainless blade in my leatherman

[HarleyXJGuy]

Forgot to post a picture.

[The Mastiff]

Some info on Cruwear and other tool steels here: https://www.bladeforums.com/threads/whi ... 2.1543958/

[dogrunner]

I carry and use my Cruwear Military a lot, including a lot of outdoor chores, and don't do any maintenance other than wipe the blade and touch up the edge as needed. The blade is not exactly shiny, but no sign at all of corrosion. I do not live near salt water, nor do I use it for game processing or food prep, just for context.

[Lancerpt]

So would that make Cruwear’s performance/corrosion resistance on par with CTS-XHP?

[bearfacedkiller]

I think it did get a very, very small bit of grey coloring towards the tip but I could only see it in the right lighting and I have never been able to capture it in a pic. I put a knife made from D2 in at the same time and it turned a dark grey.

I don’t actually like forced patinas and did it just as a test. They have both been Flitzed back to shiny since then.

BFK, how would you compare Cru-wear to ZDP-189 for corrosion resistance?

Sorry for the slow response, crazy week.

I am not sure how to even comment on it. I can best describe ZDP's corrosion resistance as odd. Kind of how I describe most of ZDP's attributes. It is a very unique steel having tons of carbon, tons of chromium and not a lot of other carbide formers plus it is a very hard steel. Having 20% chromium should make it very stainless but with a ton of carbon it really isn't. Carbon content matters a lot too. I have had it act very stainless at times and I have had it seem very reactive at other times. It also seems to patina and corrode in a unique way. It is not hard to care for but also should not be neglected. That said, I have had it patina quickly cutting up certain foods and I have never had Cruwear patina at all cutting up food so I would say Cruwear is more corrosion resistant.

I personally love ZDP and have had my Stretch2 in my pocket for over a week.

[The Meat man]

I think it did get a very, very small bit of grey coloring towards the tip but I could only see it in the right lighting and I have never been able to capture it in a pic. I put a knife made from D2 in at the same time and it turned a dark grey.

I don’t actually like forced patinas and did it just as a test. They have both been Flitzed back to shiny since then.

BFK, how would you compare Cru-wear to ZDP-189 for corrosion resistance?

Sorry for the slow response, crazy week.

I am not sure how to even comment on it. I can best describe ZDP's corrosion resistance as odd. Kind of how I describe most of ZDP's attributes. It is a very unique steel having tons of carbon, tons of chromium and not a lot of other carbide formers plus it is a very hard steel. Having 20% chromium should make it very stainless but with a ton of carbon it really isn't. Carbon content matters a lot too. I have had it act very stainless at times and I have had it seem very reactive at other times. It also seems to patina and corrode in a unique way. It is not hard to care for but also should not be neglected. That said, I have had it patina quickly cutting up certain foods and I have never had Cruwear patina at all cutting up food so I would say Cruwear is more corrosion resistant.

I personally love ZDP and have had my Stretch2 in my pocket for over a week.

Been pretty busy myself. :)

That's really interesting that ZDP-189 is like that. Like you said, at first glance any steel containing 20% chromium would seem to be super-stainless. But I suppose that with that much carbon, most of the chromium that would otherwise be helping to prevent corrosion is used up forming carbides. Especially since there isn't any vanadium or other carbide formers in the alloy.

It's definitely an odd "stainless" steel.

BTW, the Spyderco catalog says that ZDP-189 technically isn't even a steel. Why is this? Anyone know?



Edit: Sorry OP. Getting a bit off topic here.

[Pelagic]

This thread makes me want to try cuwear more than ever.

[bearfacedkiller]

I think it did get a very, very small bit of grey coloring towards the tip but I could only see it in the right lighting and I have never been able to capture it in a pic. I put a knife made from D2 in at the same time and it turned a dark grey.

I don’t actually like forced patinas and did it just as a test. They have both been Flitzed back to shiny since then.

BFK, how would you compare Cru-wear to ZDP-189 for corrosion resistance?

Sorry for the slow response, crazy week.

I am not sure how to even comment on it. I can best describe ZDP's corrosion resistance as odd. Kind of how I describe most of ZDP's attributes. It is a very unique steel having tons of carbon, tons of chromium and not a lot of other carbide formers plus it is a very hard steel. Having 20% chromium should make it very stainless but with a ton of carbon it really isn't. Carbon content matters a lot too. I have had it act very stainless at times and I have had it seem very reactive at other times. It also seems to patina and corrode in a unique way. It is not hard to care for but also should not be neglected. That said, I have had it patina quickly cutting up certain foods and I have never had Cruwear patina at all cutting up food so I would say Cruwear is more corrosion resistant.

I personally love ZDP and have had my Stretch2 in my pocket for over a week.

Been pretty busy myself. :)

That's really interesting that ZDP-189 is like that. Like you said, at first glance any steel containing 20% chromium would seem to be super-stainless. But I suppose that with that much carbon, most of the chromium that would otherwise be helping to prevent corrosion is used up forming carbides. Especially since there isn't any vanadium or other carbide formers in the alloy.

It's definitely an odd "stainless" steel.

BTW, the Spyderco catalog says that ZDP-189 technically isn't even a steel. Why is this? Anyone know?



Edit: Sorry OP. Getting a bit off topic here.

Anything over about 2% carbon isn’t considered a steel. I don’t know what to call ZDP? Stainless cast iron?

[Bill1170]

BFK, how would you compare Cru-wear to ZDP-189 for corrosion resistance?

Sorry for the slow response, crazy week.

I am not sure how to even comment on it. I can best describe ZDP's corrosion resistance as odd. Kind of how I describe most of ZDP's attributes. It is a very unique steel having tons of carbon, tons of chromium and not a lot of other carbide formers plus it is a very hard steel. Having 20% chromium should make it very stainless but with a ton of carbon it really isn't. Carbon content matters a lot too. I have had it act very stainless at times and I have had it seem very reactive at other times. It also seems to patina and corrode in a unique way. It is not hard to care for but also should not be neglected. That said, I have had it patina quickly cutting up certain foods and I have never had Cruwear patina at all cutting up food so I would say Cruwear is more corrosion resistant.

I personally love ZDP and have had my Stretch2 in my pocket for over a week.

Been pretty busy myself. :)

That's really interesting that ZDP-189 is like that. Like you said, at first glance any steel containing 20% chromium would seem to be super-stainless. But I suppose that with that much carbon, most of the chromium that would otherwise be helping to prevent corrosion is used up forming carbides. Especially since there isn't any vanadium or other carbide formers in the alloy.

It's definitely an odd "stainless" steel.

BTW, the Spyderco catalog says that ZDP-189 technically isn't even a steel. Why is this? Anyone know?



Edit: Sorry OP. Getting a bit off topic here.

Anything over about 2% carbon isn’t considered a steel. I don’t know what to call ZDP? Stainless cast iron?

My guess is that the conventional view that >2% carbon isn’t “steel” anymore dates from a time before powdered metallurgy. In ingot steels, carbon >2% will separate out as graphite nodules as the melt solidifies, i.e.- cast iron.