D2 Versus 154CM Salt Corrosion Tests

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harris2

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Has anyone a link, or have information on actual/factual salt water or corrosion tests that pit D2 against 154CM blade steels? I have the original version 710 that came with a 154CM serrated black blade that I would like to get replaced with a satin plain edge, but Benchmade will only replace it with the newer D2 blade.

I understand that D2 isn't stainless (although very close) and 154CM is stainless, what I'm looking for is real world tests, or actual hands-on corrosion experience not what a steel specifications charts shows me.

Thanks.
 
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Can only offer my personal experience with both steels. 154CM is less likely to stain/rust than D2. And S30V is even more stainless than 154CM. D2 is fine as long as you clean it after use on foodstuffs etc.
 
No scientific data here but I do carry a D2 fixed blade with me when I kayak (I keep it strapped to the front deck). Fresh water had no effect but salt/brine did leave some minor surface rust. Now i try to keep a thin coat of oil on it but even when i forget or it wears off, the rust is quick and easy to polish off.
 
Thanks guys. Humm, sweat, organic acids, e.g. blood, foods, etc. and rain is more of a concern than salt water, but still wishing for a test out there to help me decide. I still cringe from the experience I had with a knife from my younger days - left a kabar in the leather sheath for a looong time - the results wasn't pretty!
 
Helderberg said:
So, if I understand this, D2 is similar to a M2 or M4 as far as rust and discoloration?
Frank.
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Between those steels D2 has a lot more Chromium (rust inhibitor) content. I believe the requirement to be classified as stainless is 13.00% or greater Chromium content. According to Benchmade's Data Sheet:

Chromium Content:
D2 = 12.00%
M2 = 4.15%
M4 = 4.0%

So, D2 should be MUCH more stain and rust resistant than the other two. 154CM has 14.00% Chromium. The difference between D2 and 154CM isn't much, but how much of a difference does 2% REALLY make in the real world is what I'm trying to determine.


Edited to change 1% to 2%
 
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harris2 said:
Between those steels D2 has a lot more Chromium (rust inhibitor) content. I believe the requirement to be classified as stainless is 13.00% or greater Chromium content. According to Benchmade's Data Sheet:

Chromium Content:
D2 = 12.00%
M2 = 4.15%
M4 = 4.0%

So, D2 should be MUCH more stain and rust resistant than the other two. 154CM has 14.00% Chromium. The difference between D2 and 154CM isn't much, but how much of a difference does 2% REALLY make in the real world is what I'm trying to determine.


Edited to change 1% to 2%
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For what its worth, having deployed in saltwater environments for months at a time for years carrying both D2 and 154CM blades, when either is exposed to direct saltwater spray or gets wet with saltwater if you do not wipe dry and oil "soon" they will both start to develop light rust by the next day or so. No real discernable difference under those circumstances.

I've had both steels start to lightly rust in my pocket even when not used just from the environment. Regular application of Break-Free CLP kept them rust free though as long as I did the above.

D2 may rust slightly faster, exactly how much faster I don't really know but in my experience both will start to show corrosion under the right circumstances. D2 may show light corrosion after one day after exposure and 154CM might take two or three days after exposure. Not exactly scientific but what I observed. If your in an environment that is highly corrosive to steel both will require preventative maintenance (Wiping dry and oiling) to parent rust. The difference not being all that great.

Although D2 only has 12% Chromium (Just below the threshold of being stainless) vs 14% Chromium in 154CM, D2 also has other alloy's in it that contribute and support stain / corrosion resistance.

The D2 formula also has:Nitrogen 0.30%. Similar to the Carbon atom but offers and contributes to corrosion resistance. Plus, Molybdenum 1.0 %. Used mainly to increase strength & hardenability also adds to corrosion resistance.

I'm not a metallurgist but I think "maybe" the other alloys added to D2 contribute to it's overall corrosion resistance and why D2 has better stain resistance then it's 12% Chromium might suggest. Just something I thought of.

Like I said, that's my experience with both. I've never seen any side by side testing between the two though.

This might be a good question to call Benchmade and ask them. Ask to speak to a tech in customer service and see if they have data that definitively defines how much more corrosion resistant 154CM is then D2. This is data they just might have readily available.

I'd be curious to know myself.

All the best,
 
pbcg said:
For what its worth, having deployed in saltwater environments for months at a time for years carrying both D2 and 154CM blades, when either is exposed to direct saltwater spray or gets wet with saltwater if you do not wipe dry and oil "soon" they will both start to develop light rust by the next day or so. No real discernable difference under those circumstances.

I've had both steels start to lightly rust in my pocket even when not used just from the environment. Regular application of Break-Free CLP kept them rust free though as long as I did the above.

D2 may rust slightly faster, exactly how much faster I don't really know but in my experience both will start to show corrosion under the right circumstances. D2 may show light corrosion after one day after exposure and 154CM might take two or three days after exposure. Not exactly scientific but what I observed. If your in an environment that is highly corrosive to steel both will require preventative maintenance (Wiping dry and oiling) to parent rust. The difference not being all that great.

Although D2 only has 12% Chromium (Just below the threshold of being stainless) vs 14% Chromium in 154CM, D2 also has other alloy's in it that contribute and support stain / corrosion resistance.

The D2 formula also has:Nitrogen 0.30%. Similar to the Carbon atom but offers and contributes to corrosion resistance. Plus, Molybdenum 1.0 %. Used mainly to increase strength & hardenability also adds to corrosion resistance.

I'm not a metallurgist but I think "maybe" the other alloys added to D2 contribute to it's overall corrosion resistance and why D2 has better stain resistance then it's 12% Chromium might suggest. Just something I thought of.

Like I said, that's my experience with both. I've never seen any side by side testing between the two though.

This might be a good question to call Benchmade and ask them. Ask to speak to a tech in customer service and see if they have data that definitively defines how much more corrosion resistant 154CM is then D2. This is data they just might have readily available.

I'd be curious to know myself.

All the best,
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My experiences with those two steels mirrors yours. I'm a huge fan of D2, as is this guy:

B2A19A2E-0164-4756-80D1-CECA7FD16D3E_zpsdt31j6us.jpg
 
I've talked to Benchmade customer service. As expected they don't have an answer other than to quote from the "blade steel" chart on their website that most of us have already seen. However, one representative said she knows someone at Benchmade that may have the answer and will get back with me as soon as possible (probably 24-48hrs.). I'm sure there is an easily accessible corrosion test database that is archived somewhere within their basement.

I already decided to replace the serrated/black 154CM blade with the D2 satin, plain edge anyway. The 710's serrations at the recurved area of the blade increases the curvature to an extreme amount compared to the recurve on the plain edged version. In my opinion it makes for a fantastic rope cutter, but otherwise not very practical for everyday use.
 
One thing that was not said here is that we should remember that most of liners are 440C. It is chemically similar to 154CM in corrosion resistance..

Another thing to note about 154CM is that it may have pitting rust. Powder metal blends corrosion resistant metal additives such as Chromium, molybdenum, and manganese more evenly. As you know 154cm and D2 are not powder metals and it may be the reason of pitting corrosion.
 
^ Most Axis liners are actually 420 stainless, not 440. A knife manufacturer other than Buck found a good application for 420, and that's a good thing.

D2 has been alive about as long as I have (I'm 41) and far precedes any powder steels. There's a reason that more than one successful maker's made a career decision to use it exclusively for so many years -- it's good stuff.

The theoretical misinformation about its stainless-ness on the web vs people's actual experience with it is what's driving discussions and it makes about as much sense as the changes to my HMO plan this year, thanks to our current WH administration.
 
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Wolf1524 said:
In this video the guys tests corrosion resistance od Benchmade Adamas which has D2 steel...
http://www.youtube.com/watch?v=c3GLajPbBGs
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Good find, Wolf1524.

The video is very informative and interesting. It would have been even better if he had also tested a knife blade of 154CM or S30V - stainless versus non-stainless. Below is what I believe his tests verify:

1. M4 holds an edge longer than D2.
2. D2 rusts a little slower than M4.
3. D2 and M4 rust when 420J stainless liners do not.
4. Whatever stainless is used for the axis lock will rust.
5. Cerocote prevents rust.
6. Cardboard is hard on a blade's edge.
7. The 810 Contego scales are hard on your hand (happy I bought the 810-1401 with it's smoother scales :))
8. The axis lock is durable and continues to work when exposed to dirt/mud.
9. Even the best blade steels need maintenance and sharpening.

Thanks again for the link to the video.
 
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Wolf1524 said:
In this video the guys tests corrosion resistance od Benchmade Adamas which has D2 steel...
http://www.youtube.com/watch?v=c3GLajPbBGs
Click to expand...

Great video!

I remember when it first came out and I watched the whole series. What I took from it at the time in addition to what's already been mentioned is, The Comparisons of D2 and CPM-M4, not only edge retention and toughness but how well both being non stainless resisted corrosion. Far better then I would have predicted prior to watching the video. Especially the CPM-M4

Another thing was that a folder, in this case the Adamas out preformed a Carbon steel survival fixed blade. I know there are many variables here but it's generally accepted that a fixed blade is always preferable to a folder in a survival situation. Not necessarily the case as shown in this particular test.

Lastly, and this mirrors my personal experience, is the value of serrations, or a CE blade in the field.

When both plain edges had dulled and no longer cut the CE was still cutting strong. Not much of an issue for normal EDC usage but in the field when you may not have the time, opportunity, or the ability and tools to sharpen your knife the serrations significantly extend the cutting life of your knife. More then once in the field I have benefited from the fact that my knife was a CE.

Like I said, I know this doesn't apply to the vast majority of EDC needs but it does show the value of a serrated or CE blade under certain circumstances.

Great video and thanks for posting.
 
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Would it be blasphemy if I ll say that I think that BM Axis lock seems tougher to me for hard use folders than titanium framelocks like Strider or ZT?
 
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