Corrosion Testing of 9 Stainless Knife Steels
- The Mastiff
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Re: Corrosion Testing of 9 Stainless Knife Steels
Just excellent Larrin! Thank you for putting the time and work into this as usual.
Re: Corrosion Testing of 9 Stainless Knife Steels
Thanks!The Mastiff wrote: ↑Mon Oct 14, 2019 1:01 pmJust excellent Larrin! Thank you for putting the time and work into this as usual.
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Re: Corrosion Testing of 9 Stainless Knife Steels
I don't know why, but my cold steel recon 1 and broken skull do very well with my highly corrosive sweat while working on the water and occasional exposure to sea water. Cruwear, in my experience, is an absolute rust bucket compared to XHP.zuludelta wrote: ↑Mon Oct 14, 2019 10:11 amI think as far as conventional knife usage goes, XHP is "stainless enough" for 95% of the knife community and perhaps to less of an extent, the same can be said for ZDP-189 and CruWear (I carried a Dragonfly in ZDP-189 as my EDC for years & rusting/staining was never a problem with regular common sense maintenance).
That said, I have seen an XHP knife develop a notable layer of surface rust with some staining during constant exposure to seawater over a six-hour period, where a VG10 blade only developed minimal surface rust that was easily wiped away. I suppose in many of these steels, the corrosion resistance rating differences really only become practically apparent in more extreme conditions.
Last edited by Pelagic on Tue Oct 15, 2019 1:25 am, edited 1 time in total.
Re: Corrosion Testing of 9 Stainless Knife Steels
Remember that high temperature tempering is common with CruWear which reduces its corrosion resistance.
Edit: And looking at my ratings table again there is a significant difference between the two steels.
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Re: Corrosion Testing of 9 Stainless Knife Steels
I know heat treat has a lot to do with corrosion resistance. I have no long term experience with any XHP aside from that of cold steel (one particular heat treat). But I subject my knives to a highly corrosive environment and i can say they do quite well. Absolutely better than spyderco's s30v. More similar to s110v really (but not quite as good as s110v).
Re: Corrosion Testing of 9 Stainless Knife Steels
Thanks yet again for an informative read Larrin. :)
A day without laughter is a day wasted. ~ Charlie Chaplin
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Re: Corrosion Testing of 9 Stainless Knife Steels
Nice job. Very good info. Thanks!
Re: Corrosion Testing of 9 Stainless Knife Steels
Really cool stuff, thank you for sharing. This is a lot more interesting to me than how many feet of cardboard X steel cuts. There's never a time I need to cut 5,000 boxes in a single go but there's countless days during the year where my knife sits in a sweaty pocket all shift.
Surprised at how bad XHP did. I've never used it but people always reported it being pretty corrosion resistant.
Surprised at how bad XHP did. I've never used it but people always reported it being pretty corrosion resistant.
- JacksonKnives
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Re: Corrosion Testing of 9 Stainless Knife Steels
Very interesting. There was a highly-publicized case a few years back of a China-made s35vn blade with a similar patina in nearly identical conditions (cutting meat) that many armchair experts assumed must have been "fake" steel. I think eventually they got that one tested to prove it was real. A surface finish like this (I'm assuming belt finished and then buffed?) seems to facilitate strange interactions with meat juice.The Meat man wrote: ↑Mon Oct 14, 2019 9:14 amHere's what it looked like.
[images on page 1]
I could not clean it off. It gradually wore off after a few weeks of use.
Re: Corrosion Testing of 9 Stainless Knife Steels
Just goes to show the importance of doing experiments on separate specimens made the same way rather than relying on anecdotes with knives of different heat treatments and finishes. Such anecdotes may sometimes be useful when it comes to comparing knives, but may not be reliable in terms of understanding how steels compare.
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Re: Corrosion Testing of 9 Stainless Knife Steels
Larrin, what if XHP contained 2% vanadium? Would it likely be much more corrosion resistant? Since vanadium forms carbides more readily, would this result in fewer chromium carbides and this more free chromium in the matrix?
I feel 16% is a lot of chromium, however with 1.6% carbon and no other carbide formers, the amount of free chromium takes a big hit.
I feel 16% is a lot of chromium, however with 1.6% carbon and no other carbide formers, the amount of free chromium takes a big hit.
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Re: Corrosion Testing of 9 Stainless Knife Steels
Yeah it seems that under certain conditions, meat juice will react with even "stainless" steel. I recall fellow member TkoK83Spy experiencing similar discoloration on M390, from the same cause.JacksonKnives wrote: ↑Mon Oct 14, 2019 9:49 pmVery interesting. There was a highly-publicized case a few years back of a China-made s35vn blade with a similar patina in nearly identical conditions (cutting meat) that many armchair experts assumed must have been "fake" steel. I think eventually they got that one tested to prove it was real. A surface finish like this (I'm assuming belt finished and then buffed?) seems to facilitate strange interactions with meat juice.The Meat man wrote: ↑Mon Oct 14, 2019 9:14 amHere's what it looked like.
[images on page 1]
I could not clean it off. It gradually wore off after a few weeks of use.
- Connor
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"What is a man profited, if he shall gain the whole world, and lose his own soul?"
Re: Corrosion Testing of 9 Stainless Knife Steels
The Meat man wrote: ↑Tue Oct 15, 2019 8:38 amYeah it seems that under certain conditions, meat juice will react with even "stainless" steel. I recall fellow member TkoK83Spy experiencing similar discoloration on M390, from the same cause.JacksonKnives wrote: ↑Mon Oct 14, 2019 9:49 pmVery interesting. There was a highly-publicized case a few years back of a China-made s35vn blade with a similar patina in nearly identical conditions (cutting meat) that many armchair experts assumed must have been "fake" steel. I think eventually they got that one tested to prove it was real. A surface finish like this (I'm assuming belt finished and then buffed?) seems to facilitate strange interactions with meat juice.The Meat man wrote: ↑Mon Oct 14, 2019 9:14 amHere's what it looked like.
[images on page 1]
I could not clean it off. It gradually wore off after a few weeks of use.
In the end we have to remember it's stain----less..... Not stainless...
All steels will and can rust, stain etc, with the only real exception being H1 and that's not steel per say.
Re: Corrosion Testing of 9 Stainless Knife Steels
Another super thread Larrin :) Now this brings up a subject I've been meaning to talk to you about for some time now. There was a machine tool shop I worked at some time back where we did all kinds of testing. We had every type of hardness tester along with toughness testing equipment. But we had a chemical compound that some of the guys that worked there did corrosion testing with. The chemical compound was called "Aqua Regia" and they used it solely for testing corrosion on metals and coatings.
I'm just wondering if that "Aqua Regia" played a role in your testing?
I'm just wondering if that "Aqua Regia" played a role in your testing?
Re: Corrosion Testing of 9 Stainless Knife Steels
That's interesting Meat Man because over the years I've found that food acids and fats and other compounds from meat, poultry and fish all seem to have their own strange effects on various blade steels and other metals.The Meat man wrote: ↑Mon Oct 14, 2019 8:39 amExcellent article Larrin. Very interesting to see CTS BD1N way up there. I've not had any rust with it, but I have had it patina after cutting some pork chops.
Thanks as always for your contributions!
ZDP-189 being one of the very worst I've encountered as of yet.
Re: Corrosion Testing of 9 Stainless Knife Steels
Aqua regia is one of the acids that Crucible has used in their corrosion testing. I used their data including the aqua regia tests in my previous corrosion article. In my testing I did not use it.JD Spydo wrote: ↑Tue Oct 15, 2019 9:07 amAnother super thread Larrin :) Now this brings up a subject I've been meaning to talk to you about for some time now. There was a machine tool shop I worked at some time back where we did all kinds of testing. We had every type of hardness tester along with toughness testing equipment. But we had a chemical compound that some of the guys that worked there did corrosion testing with. The chemical compound was called "Aqua Regia" and they used it solely for testing corrosion on metals and coatings.
I'm just wondering if that "Aqua Regia" played a role in your testing?
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Re: Corrosion Testing of 9 Stainless Knife Steels
Why isn't H1 steel?
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- JonLeBlanc
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Re: Corrosion Testing of 9 Stainless Knife Steels
Really interesting article, and one that has a definite bearing on practical concerns!
My collection so far: 52100 Military (2); 52100 PM2 (2); 52100 Para3; Stretch2 V-Toku; KnifeWorks M4 PM2; BentoBox M390 PM2; BentoBox S90V Military; Police4 K390; S110V PM2; SS Delica AUS-6; Wayne Goddard Sprint VG-10
Wish list: Hundred Pacer; Sliverax; Mantra; 52100 PM2 SE; Kapara
Wish list: Hundred Pacer; Sliverax; Mantra; 52100 PM2 SE; Kapara
Re: Corrosion Testing of 9 Stainless Knife Steels
It's an alloy, we all had this discussion a very long time ago, like 15 years ago or so.
That's why I said per say...
I don't remember all of it, Sal can likely ring in with more info I think.
Re: Corrosion Testing of 9 Stainless Knife Steels
Most any steel can be called an "alloy steel." H1 is a steel.
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