1, carbon steel, high enough intensity, the lower the stress concentration sensitivity, easy to carry out a variety of heat treatment and mechanical processing, low price, supply adequate and there are the most widely used. The imports of general machinery bearings are available in 30,40,45,50 and other brands of high-quality carbon steel, particularly steel 45 after quenching the most commonly used.
2, through the various heat treatment, chemical treatment and surface hardening treatment can be improved with the manufacture of carbon steel or alloy steel shaft strength and wear resistance. In particular, alloy steel, and only after heat-treatment in order to fully demonstrate their superior mechanical properties.
3, the alloy steel on stress concentration sensitivity of high-alloy steel shaft so the structure of the shape must be reasonable, otherwise we lose the significance of using steel.
4, the alloy steel of high mechanical properties, commonly used in the manufacture of high-speed, heavy shaft, or under large demand small size, light weight shaft. For those in the high temperature, low temperature or corrosive media work axis, most manufacturers use steel. Imports of steel bearings are commonly used: 12CrNi2, 12CrNi3, 20Cr, 40Cr, 38SiMnMo so.
In the rolling surface roughness and lubrication adverse circumstances. Spalling will develop into a spin-off. This has resulted in ntn bearing spalling, described below under the ntn bearing spalling occurred after the three kinds of solutions:
The first control surface roughness, to prevent rust.
The second select the appropriate lubricant.
3rd reasonable assembly.