Super Duplex (S32760) and 15-5PH Galvanic Corrosion 1

[lukaszd]

Hi all,

Could you please tell me whether there is a galvanic corrosion risk (or how to calculate the corrosion potential) between the following stainless steels:
- Super Duplex (S32760)
- 15-5PH Galvanic Corrosion

Many thanks,
Lukasz

 

[EdStainless]

The super duplex has much higher corrosion resistance.
15-5PH will not be quite as good as 304, so if they are coupled, and there is not something done to suppress it I would expect the 15-5 to suffer galvanic accelerated corrosion.
One option is to coat the superduplex.

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P.E. Metallurgy, Plymouth Tube

 

[mcguire]

What would mitigate what Ed says, which is correct, is that the corrosion current which occurs in the galvanic circuit may be negligibly small. While the 15-5 will be anodic to the 32760, if it is still in the passive region in the media in question, it may actually benefit from anodic protection. So, the answer is, as is often the case in corrosion; it depends.

Michael McGuire

 

[SJones]

http://resource.npl.co.uk/docs/scie...publications/online_guides/pdf/bimetallic.pdf

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.