UKH

Does anyone with a bit more in-depth knowledge know if there would be any problems using Fixe's PLX (Duplex 2304) bolts with Petzl Coeur (316L) Stainless hangers? 

Thanks in advance. 

Quite simply, don't mix metal types as you'll end up creating the potential for galvanic corrosion. A4/316 stainless bolts can be purchased from hardware suppliers at relatively cheap prices - just don't trust the stupid cheap Chinese distributors! 

From personal experience, I'd avoid the PLX bolts. Some I installed recently were showing signs of corrosion within 3 weeks - rusting around the threads/washer, not just surface tarnishing where they'd been hammered home.

I would n't expect there to be a major issue based on material specification. The duplex bolt should have greater corrosion resistance on the basis it is a dual phase stainless steel (austenitic and ferritic grains) versus austenitic only 316L. While corrosion (typically pitting or crevice) initiates in the austenitic phase, the ferrite phase limits the corrosion propagating at the grain boundary whereas no separate grain boundary cannot stop the corrosion growth by structure alone. 

There's negligible difference in the electro chemical series so forget about serious galvanic corrosion.

Material quality is a different issue however and Fixe's PLX range has suffered in this regard with examples available through open source searches of the web.

 

There are some "interesting" articles on galvanic corrosion between the phases in duplex steel