Is low temperature or high temperature beneficial for bearing parts processing?

---

Bearings usually work in high-strength conditions, so conventional heat treatment is (830 ~ 860) ° C martensite quenching + (160 ~ 180) ° C low temperature tempering – this is also the best heat treatment specification to ensure the fatigue strength of bearing parts. The low temperature tempering that must be carried out can reduce the internal stress and brittleness of the material under the premise of maintaining high hardness and good wear resistance, so as to avoid premature damage such as cracking during use.

The influence of raw materials and heat treatment on bearing precision, first, whether it can have good processability, especially the characteristics of precision finishing such as grinding and superfine; secondly, whether it can have good size during storage and use. Stability, without loss of machining accuracy.

Aluminum Vacuum Brazing Furnace

(1) After quenching and tempering, the bearing steel is a high-hardness material, which is more suitable for grinding, but the brittle inclusions present in the steel are easy to fall off from the metal substrate during the grinding process of the parts, causing scratches and affecting Finished surface quality.

(2) Conventional heat treatment requires the bearing to maintain dimensional stability at a working temperature of 120 ° C or less. However, even some general-purpose bearings, due to the main purpose, have formed basic technical features that are different from conventional requirements. For example, spherical roller bearings are often used for vibration and impact conditions, and are prone to high temperatures.

Therefore, SKF, FAG, Timken, NTN and SNR standard bearings are required to maintain dimensional stability below 200 °C; precision bearings require cold treatment after quenching (reduced unstable austenite structure after quenching), Additional tempering (eliminating grinding stress and stabilizing the structure) during the grinding process, some companies’ standard precision machine tool bearings are required to withstand 150 ° C operating temperature.