Finding a steel grade that meets performance expectations at elevated temperatures can be challenging. In this post, we’ll examine high temperature alloy steels, how working temperature affects performance, and discuss some potential grades that can handle demanding applications.
How High Heat Affects Steel Performance
Certain mechanical system components, such as bearings, shafts, and gears, are likely to experience elevated temperatures. Fast rotational speeds, extended working times, or hot work environments can all affect steel performance. Manufacturers may use high temperature steel grades when applications reach temperatures of ~250°F (120oC) and above.
High temperature steel alloys are niche materials that not only perform at ambient conditions but also when temperatures increase. These types of steels are required in aerospace for jet engine bearings and other demanding applications that often necessitate a combination of properties, such as hardness and corrosion resistance, at temperatures well above ambient.
Not all steels maintain their properties at elevated temperatures, and many with acceptable characteristics under “ordinary” conditions perform inadequately when subjected to high heat. An example is 52100 bearing steel. A widely used grade for standard service, 52100 experiences a substantial hardness loss in harsh conditions.
Potential issues related to excessive heat on a metal component include:
- Hardness reduction
- Thermal expansion
- Corrosion acceleration
- Shortened lifespan
Selecting the “right” steel involves fully understanding your application. It’s wise to consider the impact of the maximum and ongoing operating temperatures, projected loads and speeds, thermal expansion, and corrosivity.
The best approach for a critical component may involve adjusting operational parameters as well as investigating specialized coatings or heat treatments, and—of course—identifying options such as high temperature alloy steels.
A Look at Sullivan’s High Temperature Alloy Steels
Sullivan Steel offers high-performance options for when conventional grades exceed their service limits. Depending on requirements, we offer solutions with exceptional hardness, corrosion resistance, and longevity in elevated-temperature environments.
There are several ways to mitigate the effects of elevated temperature on metals. Steel mills design their products to include (or exclude) specific chemical elements in order to deliver superior performance. Likewise, mills have processing options, such as vacuum arc remelting, to manufacture metals with exceptional cleanliness. Other methods for improving a metal’s heat resistance include surface coatings and treatments.
Sullivan sells and supports high temperature alloy steels, such as:
The best way to select and treat a steel part for elevated temperatures will always be application-specific.
Find the Right High Heat Alloy for Your Application
Getting the right steel for your project means balancing cost and performance. While standard grades may meet design criteria like hardness and corrosion resistance at ambient temperatures, specialty alloys may be better for critical components under high heat conditions, especially if the consequences of failure are severe.
Understanding a metal’s full potential is crucial to making informed decisions, and Sullivan offers expert support for all the steel we sell. Talk with our engineers and metallurgists if you’re unsure about selecting a grade for your high temperature application.
