Galvanic Corrosion Due to dissimilar metals?

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VorpelSword

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In industrial applications, there are installations that reqiore the use of "sacrificial anods" to protect the primary equipment from corrocion. The scrificial part is a piece of lessor metal that corrodes preferentially instead of the other metal parts, and is replaced s needed. This technique is also used in ships and boats,

Does this ever occure with pattern welded steels where steels of different formultions are in intimate contact? I am thinking of combinations where a stainless steel is in contact with a carbon steel especially.

My coffee fueled guess is no, or there would be ssome talk about that already.

What about the use of non-steel metals for fittings; guards, spacers, pommels and such?
 
In anodized applications the sacrificial metal has to have the high ability to gain electrons. This is reduction potential. Hence zinc is an excellent metal and used in boating applications. Iron does corrode but not at the rate of zinc. Additionally, you must be in an environment conducive to the reaction. Can a carbon steel corrode with a stainless steel mix, yes, but it would be superficial and repairable.
 
Technically yes. But all metals do not react the same way. See the attached table. Carbon steel to stainless or nic kle should be such a big deal as far as galvanic is concerned. Cant really comment on the mechanism of GC as I did not do so well in metallurgy in college. I think in the case of properly made damascus with no to very few inclusions, there should not be much galvanic action going on. I do see it in the form of rust on some less than perfect damascus.
 

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Never seen this happen with knives myself. But thirty years in the hvac business I’ve seen plenty of boilers and water heaters etc with this happening.
 
VorpelSword said:
In industrial applications, there are installations that reqiore the use of "sacrificial anods" to protect the primary equipment from corrocion. The scrificial part is a piece of lessor metal that corrodes preferentially instead of the other metal parts, and is replaced s needed. This technique is also used in ships and boats,

Does this ever occure with pattern welded steels where steels of different formultions are in intimate contact? I am thinking of combinations where a stainless steel is in contact with a carbon steel especially.

My coffee fueled guess is no, or there would be ssome talk about that already.

What about the use of non-steel metals for fittings; guards, spacers, pommels and such?
Click to expand...
Spent a goodly number of years as an aerospace materials engineer. Corrosion prevention was one of my areas of expertise.

Galvanic corrosion requires three conditions in order to occur:
> A galvanic differential. (dissimilar metals. Carbon steel and stainless steel are dissimilar enough to present such a differential. )
> electrical contact between the two metals.
> an electrolyte path contacting both metals.

So, with carbon steel / stainless steel, you have the first two bullets, but not the third. Don't stick the knife in a jar of tap water and you should be OK.

When using two grades of stainless steel, there is not a sufficient galvanic differential to cause an issue.
 
knarfeng: Thank you for that concise and expert explanation.

I guess that these questions are moot in that if it were a real issue in knife making, there would be a whole forum on just that subject.
 
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