Corrosion on metal

Engineering support

Can stainless steel corrode?

It’s a question many people do not consider because there is a common assumption that stainless steel cannot corrode. But the answer is yes, yes it can.

Despite being a naturally corrosion-resistant metal alloy, there are some kinks in the armor of stainless steel, including crevice corrosion, ferritic contamination, and passivation issues. Let’s consider passivation issues. Passivation is a cleaning operation that occurs post processing to remove contaminants and ensure that the component is inert to corrosive reactions. If the issues exist within the passivation process, the component may corrode, despite the expectation of resistance to corrosion.

So how do  you prevent corrosion in stainless steel components? There are several testing methods available, including copper sulfate testing, high humidity testing, and salt spray testing. Each has its own advantages and disadvantages.

For the stainless steel to perform effectively and resist corrosion, it is critical that the parts be passivated and tested properly.

As a naturally-corrosion resistant metal alloy, stainless steel is the material of choice where extended part life is required. The material’s ability to self-passivate gives it longevity that is unmatched by sacrificial coatings in real-world settings. However, one must use caution with stainless steel, and must understand that it is not impervious to rust. Properly passivating stainless steel parts, and testing them appropriately, is vital to ensuring that they meet your expectations.

To learn more about the kinks in stainless steel’s armor and passivation testing methods, check out our white paper Corrosion of Stainless Steel: Test Methods and Proper Expectations published by Appliance Design Magazine and available to you through our website. Or, as always, contact us with questions any time.