Would zinc coated 4043 steel with 17-4 SS produce corrosion? 1

[mexmech]

Hi,

If I make a “sandwich” of 2 plates of zinc plated 4043 steel with a 17-4 SS link, would they produce corrosion?

Thank you

 

[Metalguy]

Not if it's dry! Otherwise you have the makings of a battery there.

 

[MikeBurns]

Also, zinc plated 4340 is susceptible to hydrogen stress cracking (aka hydrogen embrittlement) in a corrosive evironment if the hardness exceeds about 35 HRC, equivalent to a tensile strength of about 157 ksi.

17-4 PH can also be susceptible to hydrogen embrittlement coupled to zinc in corrosive environments.

 

[mexmech]

Thanks for the replays.

So if this assemble is outdoors (on a crane) a rain or humidity will produce corrosion, right?

What could be a simple way to threat the 4340 steel in contact with SS to avoid corrosion while being outdoors?

 

[hacksaw]

you question has been answered in part, if it is continuously exposed to an electrolyte(conductive) solution you may have a problem.

defining the degree of concern further definition of your question and possible testings.

ss tends to passivate and reduce the level of concern, but there are a lot of environments that can breakdown the passivation and trigger corrosion.