For bearings, corrosion is an often undetected and deadly enemy. While stainless steel and chrome steel bearings are designed to be resistant to corrosion, they are still vulnerable, particularly when stored incorrectly in harsh environments, where humidity and condensation can ultimately lead to rusting. Even the smallest exposure to chemicals, dirt and other contaminants, can increase the risk of corrosion and significantly reduce the life of your bearings.
By the time rust appears, it’s usually too late to save your bearing. Deep-seated rust is caused by prolonged exposure to water, forming grey-black streaks, cracks, flakes and premature bearing failure. The true cost of rust is measured by the downtime it causes and the costly replacement of machines components, so prevention should always be your first line of defence. Here, we detail the four most successful ways to protect your bearings from corrosion.
To improve the corrosion resistance of standard steel bearings, choose a design that uses stainless-steel balls. These bearings typically use standard grade 400 stainless-steel which has a decent load capacity as well as moderate corrosion resistance. For even better resistance, grade 300 stainless-steel bearings are available; however, their load capacity will be reduced. Hybrid bearings, using ceramic balls and stainless-steel races, are the ultimate choice for effective rust prevention. Ceramic is chemically inert, making it highly resistant to corrosion, and hybrid bearings in the right applications have been known to run faster, operate at higher temperatures and further reduce vibration.
By applying a protective coating to your bearings, you can create a barrier that should prevent contaminants from reaching the bearing surface. In some cases, the inner and outer rings are both covered in a protective coating, of which the most common types are chromium and nickel plating, zinc thermal sprays, and black oxide. An added benefit of a protective coating is that it hardens the raceways and increases the life of the bearing.
For bearings that are used in highly corrosive environments, a tighter, stronger seal, made from higher-quality materials, is often an effective method for preventing rust. Specially designed seals that can prevent water, micro-dust and chemicals from penetrating the bearing, are often the first and best choice for resisting corrosion.
In an environment where machinery is constantly exposed to humidity or moisture, a water-resistant grease or lubricant is a safe bet to ward off rust. The grease acts as a protective coating, creating a barrier between the surface of the bearing and any possible contaminants. It’s important, however, not to use too much grease, as this can cause its own set of problems.
If you’re concerned about corrosion, but you’re not sure how to get started or if you need additional advice, do the necessary research or give our helpful team a call. We can assist you in choosing the correct the bearing for the job and advise on why it’s the best option for your specific application. At Bearing Centre, we won’t let you down!