Anyone familiar with 440C should agree it’s the “go-to” steel for corrosion resistant bearings. It offers decent hardness and resistance to wear and corrosion. However, many designers also know that 440C, while versatile, still corrodes in challenging environments.
Sullivan Steel offers a selection of alloys ideal for highly critical corrosion resistant bearings. In this post, we’ll look at some of the specialty metals worth considering when early failure isn’t an option.
Why Use Specialty Metals For Bearings?
Using specialty-grade steels for your corrosion resistant bearings is one way to design for better performance and longer service life. Performance steels can translate into dependability—a crucial attribute when failure has serious consequences.
Specialty metals have unique advantages such as:
- Bearing-quality hardness that doesn’t sacrifice corrosion resistance
- Micro-structures that withstand wearing, galling, and cracks
- Performance increases at costs comparable to basic steels
The Best Steel Grades For Corrosion Resistant Bearings
A deep understanding of the performance needed from your bearings, and the environment they’re exposed to, is key to choosing a steel grade for your application.
Here are some specialty steels ideal for corrosion resistant bearings.
XD15NW® Bar
The highest performing corrosion resistant bearing steel that Sullivan carries, XD15NW® combines extreme hardness with extreme corrosion resistance that is vastly superior to 440C. Other steels sacrifice one of these properties to the benefit of the other. With XD15NW® you get high performance in hardness and corrosion resistance at the same time.
XD15NW®’s fine-grained microstructure gives it superior performance when it comes to resisting fatigue, wear, galling, crack propagation, and (of course) corrosion.
This nitrogen-rich remelted grade is suitable for high-stress, flight-critical aerospace applications; it supports components such as actuation hardware and airframe control bearings.
XD16N Bar
XD16N is an air-melted grade that balances performance and cost. It has a high temperature tolerance superior to other nitrogen grades of bearing steels, achieves a Rockwell hardness of at least 58 after tempering, and has fatigue and corrosion resistance vastly superior to 440C VAR (vacuum arc remelted).
In the aerospace industry, non-flight critical parts, such as cargo rollers and rescue hooks, may be made of XD16N. And, for medical applications, XD16N can get harder and is less susceptible to wear than precipitation hardening (PH) grade steels.
CX13VDW Bar
A cost-effective remelted stainless steel designed to accept carburization easily, CX13VDW is suited to applications where a high hardness level is desirable on a component’s outer surface while maintaining core toughness.
Prevalent uses of CX13VDW include corrosion resistant bearings and rod-ends, aerospace ball screws, shafts, and more. This fully stainless metal grade retains its corrosion resistance (except where carburized) and performs very well in corrosive environments.
BG-42 Bar
Designed for critical aerospace and bearing applications, BG-42 combines high hardness and excellent corrosion resistance (due to its high chromium content and use of cobalt as an alloying element). The double vacuum melting process ensures cleanliness, and the steel can perform in temperatures up to 900F.
BG-42 is also popular for cutting tools requiring superior edge retention.
Sullivan’s Offerings for Corrosion Resistant Bearings
Demanding environments call for alloys with properties that maximize corrosion resistance, hardness, and performance. Sullivan Steel offers a range of metals suitable for corrosion resistant bearings, including XD15NW®, XD16N, CX13VDW, and BG-42….as well as 440C.
At Sullivan, we support the steel we sell. If you’re facing a challenge with corrosion, our engineers and metallurgists will help you understand why and can assist with selecting a steel grade that fits your needs. Talk to one of our experts about our specialty corrosion resistant steels.
