Summary for saltwater spray fog Discussion
Saltwater spray/fog vs. submersion is the core question here: Scott Olson asked which test is more aggressive for stainless steel when a customer wants 90 days in saltwater submersion with no rust. The answerer said the salt fog test is by far the more aggressive because air must reach the metal surface for rust to form. They noted that chlorides in salt water are corrosive to stainless, but after 90 days in submersion you may not even be able to measure weight loss. The response also pointed Olson to NACE corrosion handbook data, available through college engineering libraries, for more detailed guidance on this type of testing.
Q. Recently, the question has come up whether salt spray/fog or a saltwater submersion test is more aggressive. A customer needs to test stainless steel for 90 days in a saltwater submersion test with no indication of rust. Simply put, is spray/fog or submersion the more aggressive test to determine whether rust will appear.
Thank you.
Scott Olson
Aero-Space Fasteners and Electronics – Minneapolis, Minnesota, USA
2004
2004
A. The salt fog is by far the more aggressive test. Air must reach the surface of the metal for rust to form. The chlorides in salt water are corrosive to stainless, but you probably will not be able to measure the weight loss after 90 days.
NACE has a corrosion handbook with good data on this kind of thing. It’s available at any college engineering library.
Jeff Watson
– Pearland, Texas