Corrosion Resistance of CPM-M4

[TotalDbag]

What is the corrosion resistance of CPM-154 when it's BK1 coated, When compared to S30V??

 

[yoda4561]

What is the question again? CPM M4 has low corrosion resistance. It's higher than a plain carbon steel but not even close to even the less rust resistant stainless steels. CPM-154/154 CM is in practical terms about as rust resistant as S30v, when coated any stainless steel is practically rustproof except at the edge and wear areas in the pivot.

 

[RevDevil]

Classic topic and question, there is a ton of information available. You can find even more if you search through some threads.

http://www.bladeforums.com/forums/s...rrosion-Resistance?highlight=Cpm-m4+corrosion

http://www.bladeforums.com/forums/s...els-stain-and-rust?highlight=Cpm-m4+corrosion

http://www.bladeforums.com/forums/showthread.php/993329-Rust-Danged-Rust?highlight=Cpm-m4+corrosion

http://www.bladeforums.com/forums/s...-M4-steel-question?highlight=Cpm-m4+corrosion

 

[shqxk]

M4 rust pretty easily from my experience with Spyderco GB.

 

[mkjellgren]

M4 is a carbon tool steel and will rust easily if not maintained, however, any coating on an m4 blade should basically completely solve that problem. Coated m4 will not rust, but the sharpened edge and any laser engraved markings can oxidize and rust if neglected. All in all, unless you are putting the knife into storage for an extended period of time, treat coated m4 like stainless.

 

[PitbullShogun]

CPM M4 has very poor corrosion resistance as it is a tool steel. M390 has far better corrosion resistance as it has significantly higher chromium and vanadium content.

 

[Wet Noodle]

It corrodes, sure, but not badly, IMHO. I have lots of chisels, plane blades, scrapers... they all corrode in the salt water environment that I'm around all the time. It really takes minimal effort to take care of my tools and none of them have stainless cutting edges. Stainless just don't cut the mustard in my profession.
My Spyderco GB has a pretty decent patina on it and I kinda like it.
It makes me look more experienced.