304 SS for Marine Applications
304 SS for Marine Applications
(OP)
It has been suggested that 304 SS that has been electropolished has the chromium brought to the surface making the 304 SS part more corrosion resistant. I am wondering if this is a reasonable alternative to using 316 SS for marine applications. To be more specific, I am thinking of applications on boats such that the parts are not in direct contact with the ocean water under normal circumstances, but they are in the marine atmosphere and exposed to rain, limited splashing, etc.





RE: 304 SS for Marine Applications
Check out the following website for information on saltwater corrosion.
www.marfas.com
Come back with a little more information about the usage.
Is this a one of or do you plan to make several?
What is the general shape?
RE: 304 SS for Marine Applications
RE: 304 SS for Marine Applications
I have lost some Quench Annealed and electropolished 304 S/S parts that we under very low stress, roller fishing guides.
RE: 304 SS for Marine Applications
RE: 304 SS for Marine Applications
Two things that will definitely enhance your corrosion resistance much more than EP is minimization of inclusions, particularly sulfides, and specifying higher molybdenum levels, as stated by nickt1960. Free machining grades of stainless contain sulfur near the max permitted, and are particularly susceptable to end-grain chloride corrosion attack, initiated at the interception of the sulfide inclusions with the end-grain surface.
RE: 304 SS for Marine Applications
Avoid abraded surface finishes; they are death. Electroploishing is quite beneficial.
Rath Manufacturing makes a 316L tubing that has a proprietary addition that results in a critical pitting temperature of over 20C at 16%Cr and 2.0% Mo. This is nearly equal to 317. They haven't advertized it yet, but may accept orders.