M390 Corrosion test

shinyedges

shinyedges

Unfaltering Love & Undeviating Will
Joined
Jun 5, 2012
Messages
28,873
This is an old blade from a zero tolerance 0620cf that I carried and used for more than a year starting back in 2015 I think. I used this blade for everything from food prep to swimming in the ocean, rivers, lakes many times not being maintained until I got home several days later in some instances. I have never seen this hunk of m390 stain or rust in anyway. I ended up selling the 0620cf but kept this blade, it was sold with a new blade out of 204p.

I know this steel WILL rust, I just have never seen it rust in real world use in the time I owned and used it. So we will see what it takes to force some corrosion on m390.



The blade was washed with dawn dish soap and scrubbed with alcohol and dried to remove all oils



I labeled the areas with what we will be testing it with today :
Sea salt
Horseradish mustard
apple cider vinegar



Here is the sea salt:







Here is the mustard:



Here is the vinegar:




Here is the blade with the sea salt, mustard, vinegar: I tried to get the sea salt, mustard and vinegar on both the stonewashed and satin surfaces.




Here is the time everything went on:



I won't stop until I see some serious freaking rust. :D I will up the ante if I don't get the corrosion levels that I know can be forced!
 
Last edited:
I'll use this spot to post updates on the blade but for now, my pooch! I her got while stationed at fort bliss tejas! She was a squirt at the time..








Here is roughly 1 hour later:



Here is roughly 2 hours later: Notice the water evaporating from vinegar and salt, I can see no corrosion or red rust forming yet.



Here is roughly 3 hours, no discernible changes. Notice the apple cider vinegar crept under the tape.



This is at 5:45 am




This pic was taken at 5:45 am this morning notice the red in the salt in the top corner.

best image hosting websites
 
Last edited:
Over all, I did see some red specks from the salt in the very corner on the stonewash. They seem to have gone away mostly from rinsing and drying. I have a few more pics to upload later. No rust from mustard or vinegar.

The mustard appeared to have left a residue on the surface, I rubbed it with my finger and it seemed to come off. I'll have to wash the blade with soap and water with a sponge and see if any of the residue remains. I suspect not.
 
Last edited:
shinyedges said:
Over all, I did see some red specks from the salt in the very corner on the stonewash. They seem to have gone away mostly from rinsing and drying. I have a few more pics to upload later. No rust from mustard or vinegar.
Click to expand...

I feel like when Bohler invented m390 they accidentally stumbled upon an absolute miracle steel. How can a steel be easy to sharpen and yet hold an edge well? Ontop of that it appears to be greatly rust resistant.

Now I want to see some tests on how tough it is.

Thank you for sharing this! I love these threads that expand our knowledge.
 
Last edited:
I agree, m390 has been superb for me, I sharpened it quite a bit. As you know the 0620cf is a tanto and the blade you see me testing has had a minor shape change to create a small belly. Through the 1 to 2 years I used and carried this blade it under went many sharpenings and did everything I asked without issue.

Glad I could contribute.
Lapedog said:
I feel like when Bohler invented m390 they accidentally stumbled upon an absolute miracle steel. How can a steel be easy to sharpen and yet hold an edge well? Ontop of that it appears to be greatly rust resistant.

Now I want to see sone tests on how tough it is.

Thank you for sharing this! I love these threads that expand our knowledge.
Click to expand...
 
You test should be longer. Following a scenario of using the knife, pocketing it, forgetting about it while using another knife for a few days, then remembering and finding the knife, that has been sitting dirty for a few days.
 
microbe said:
You test should be longer. Following a scenario of using the knife, pocketing it, forgetting about it while using another knife for a few days, then remembering and finding the knife, that has been sitting dirty for a few days.
Click to expand...
True, that is a plausible scenario. I could let it sit in a tube of salt water for 2 days. I think all that would achieve is a speckle here and there of rust, but meh.
 
shinyedges said:
True, that is a plausible scenario. I could let it sit in a tube of salt water for 2 days. I think all that would achieve is a speckle here and there of rust, but meh.
Click to expand...

That's how I first stained my K390. LOL. I cut up a few slices of lemon for some alcoholic beverages, and then put my attention to the beverages and forgot about cleaning the knife.
I then used another knife for a few days. Wen I picked up the the K390 again I was like WTF!
 
microbe said:
That's how I first stained my K390. LOL. I cut up a few slices of lemon for some alcoholic beverages, and then put my attention to the beverages and forgot about cleaning the knife.
I then used another knife for a few days. Wen I picked up the the K390 again I was like WTF!
Click to expand...
LOL I've done the same thing! When I get home I'll throw it in salt water for a few days. Then I think I'll test it to failure.
 
Thanks for doing this test on a M390 steel knife blade, your test also shows how ZT heat treats this type of steel, to keep it's ability to resist all types of corrosion.
 
thanks!! I would like to see 24h in salt water for sure! that would be the scenario of being exposed to a beach vacation ;-)
 
You must log in or register to reply here.
Back
Top