Surface strengthening of bearing steel
Bearings are machines used to reduce friction between moving parts and are classified into rolling bearings, plain bearings and spherical bearings. Bearing steel is an important material used to manufacture bearings. It is highly desired for its high strength and fatigue properties. However, even the highest-grade base steel may suffer from unfavorable wear, fatigue and corrosion due to environmental conditions and use. Therefore, surface strengthening of bearing steel is an important task that needs to be completed to ensure optimal performance and longevity of bearing components.
The surface strengthening of bearing steel can be achieved through several approaches. The most commonly used methods are mechanical surface treatments such as hardening, grinding, honing and polishing. These processes create surface compressive stresses which can improve surface hardness, wear resistance, fatigue life and corrosion resistance. Another method is surface coating. This method involves the application of various coatings such as electroless nickel, chrome, and titanium nitride to the bearing steel surface. This provides an extremely hard and wear-resistant barrier which can protect the steel against environmental conditions. Vacuum heat treatments, material modification and laser peening are also used to strengthen bearing steel.
The hardening process involves heating and quenching the bearing steel to improve its hardness and tensile strength. This is done by heating the bearing steel to a specific temperature followed by rapid cooling. Heat treatments such as carburizing, quenching and tempering can also be used to harden bearing steel surfaces. Grinding, honing and polishing are used to improve the surface quality and reduce surface roughness of bearing steel. These processes can also increase its hardness and wear resistance.
The surface coating process involves applying a coating material to the bearing steel surface to enhance its wear, fatigue and corrosion resistance. Different coatings such as electroless nickel, chrome and titanium nitride can be applied. These coatings provide a high degree of protection against environmental conditions and can increase the bearing’s life. Vacuum heat treatments are also used to modify the surface and internal structure of bearing steels. This process can improve the surface hardness, wear resistance, fatigue life and corrosion resistance of the bearing.
Material modification and laser peening are advanced surface treatments used to further strengthen bearing steels. In laser peening, the bearing surface is subjected to a series of high-intensity laser pulses. This induces compressive stresses which can improve surface hardness and fatigue life. Material modification methods such as surface alloying, surface deposition and laser cladding, involve adding additional alloying components to the bearing steel surface. These methods provide an external layer with improved mechanical properties.
In conclusion, surface strengthening of bearing steel is essential for optimal performance and longevity of bearing components. Hardening, grinding, honing, polishing and coating processes are the most commonly used methods for strengthening bearing steel. Vacuuming, material modification and laser peening are more advanced methods used for the same purpose. All of these techniques can improve the surface hardness, fatigue life and corrosion resistance of the bearing steels.
