Generally speaking, the majority of bearings, cam followers, and other rolling elements are manufactured from AISI 52100, a degassed low-alloy chrome steel blend with significant concentrations of chromium and carbon. AISI 52100 has high hardness ratings and excellent resistance to wear and deformation.
These properties, among others, make AISI 52100 an ideal material for ball bearing and roller bearing applications. Highly versatile, AISI 52100 bearings are used in a wide range of industries, from mining and material handling to recreation and power generation.
However, standard AISI 52100 bearings are unable to withstand severe environments, so special materials are often needed to produce rolling components. For these circumstances, AISI 304, AISI 440, AISI 630, titanium, ceramic, and grease-free bearings may be used.
When choosing the right type of bearing material for your specific application, the following conditions should be kept in mind:
Corrosive Environments
Many industries operate in notoriously corrosive environments, including the food processing, semiconductor, metal plating, medical equipment, and military markets.
In the food processing industry alone, as much as $2.1 billion is spent every year repairing corrosion-related damage. Food processing generally involves a large amount of water, which is corrosive; highly acidic foods, such as jams, salad dressings, and pickles, are even more corrosive. This type of environment can lead to quick degradation of equipment, costly repair shutdowns, and food contamination.
Equipment in both the semiconductor and medical industries are also subject to stringent cleaning, decontamination, and sterilization procedures which often involve the use of harsh, corrosive chemicals. Metal plating processes require both alkaline and acidic treatments. The military has strict corrosion-resistant requirements for equipment — including vehicles, weaponry, and other machinery — to help it withstand harsh environmental conditions.
For all of these highly corrosive environments, standard AISI 52100 bearings fall short; specialized corrosion-resistant bearings are required to ensure proper functioning. Working in these scenarios, you should consider bearings made out of materials such as titanium or AISI 304, AISI 440, or AISI 630 stainless steel.
High-Temperature Environments
Many industrial processes involve temperatures of at least 400 degrees Celsius (752 degrees Fahrenheit).
During corrugated cardboard manufacturing, for instance, a series of rollers is used to crimp the central flute and adhere to the outer sheets to the flute. These rollers are heated to about 365 degrees Fahrenheit. To ensure proper functioning, specialized temperature-resistant bearings are required. Metal processing also requires very high temperature and corrosion resistance, as pH levels fluctuate during processing.
Ideal temperature-resistant bearings will be made of AISI 304 or AISI 630 stainless steel, as these metals feature both high temperature resistance as well as high corrosion resistance. Grease-free bearings are another good option, as bearing lubrication frequently breaks down in high-temperature conditions.
Electrically Charged Environments
Electrical current can be incredibly damaging to metal components. For bearings, it can cause a wide range of problems, including fluting in the races, pitting of the ball bearings, and degradation of lubrication. Electric motors of all kinds, electric traction motors in railroad applications, and medical equipment such as magnetic resonance imagers (MRIs), for instance, all involve high-stress environments with a great deal of electrical activity.
Ceramic bearings, as well as ceramic insulated metal bearings, are ideal for highly electrically charged applications. Ceramic materials, with a few rare exceptions, are very poor conductors of electricity; although they can accept large voltages, they are able to dissipate that electricity extremely effectively. The passing electricity causes little to no degradation.
Severe Environment Bearings from Emerson
Emerson Bearing Company has been an industry-leading ball and rolling bearing distributor for more than 50 years. With a sourcing network that spans the globe, we can provide bearings for virtually any application, including severe environments. Our selection of harsh-environment bearings includes:
• Ball and roller bearings from GMN, KOYO, and others
• Cam followers and yoke rollers from Carter, IKO, and others
• Rod ends from Durbal and FK
• Oil seals from Garlock, Dichtomatik, and Timkens
• Mounted units from AMI, IPTCI, and others
• Roller chains from Daido, Hitachi, and Drives
• Bushings from IGUS and Oilite
To learn more about our harsh-environment bearings or to learn how we can help you with your next project, visit our comprehensive ball bearing catalog today.
