Can Stainless Steel Rust?
With my experience, yes it can!
I am writing this as a result of an experience I had 11 years ago, when supplying stainless fasteners for a high profile contract on the Verrazano Bridge.
As most of you would know, the Verrazano Narrows Bridge was the longest suspension bridge in the world from 1964 to 1981. With a central span of 4,260 feet, this bridge marks the gateway into the New York harbor, therefore all ships arriving into the ports of New York and New Jersey, pass beneath it. This bridge carries 13 lanes of interstate traffic into and out of Brooklyn, New York. Source below.
Fasteners Direct was contracted to supply stainless steel bolts for a cable armor system being installed in 2009-2010. This system was designed to protect the structural cables of the bridge from the extreme heat of a possible auto accident or a terrorist attack.
Fasteners Direct supplied high-grade stainless steel bolts for this project. The bolts were USA made and certified as per F593 Group 2 Condition A, with all proper documentation.
The shields were assembled in Maryland, and transported to the site via truck convoy. Upon arrival to the site, the bolts holding the shields together were showing signs of rust. Now, this was a real problem!
Fasteners Direct hired some top metallurgists in the country to investigate why this happened. The test results showed that the bolt manufacturer had run a lot of steel bolts just prior to starting the stainless steel lot. The machine heads were contaminated with steel, resulting in minute particles of steel getting embedded into the surface of the bolts.
The bolts were indeed rusting, but only on the surface. We then took the bolts and shipped them to Buffalo, New York. Once they arrived, they were immersed in a pickle passivation liquid that etched all of the steel particles from the bolt surface. Once this process was done, the bolts had a dull clean look, they were not shiny like traditional stainless bolts. However, we are 10 years and counting with no report of rust on our bolts.
Anyone else out there have a real life experience with stainless rusting? We would love to hear about it!
Source from second paragraph: https://en.wikipedia.org/wiki/Verrazzano-Narrows_Bridge