All Information of The Difference between the Two Bearing Steel Materials

time2021/09/14

: This article will introduce you to two steel materials(chromium steel and stainless steel.) that are used in bearings, and the difference between them.

All Information of The Difference between the Two Bearing Steel Materials

Today I will introduce you to two bearing steel materials and how they are different.

What is The Common Bearing Steel?

Generally speaking, the steel used for bearings is called bearing steel. Bearing steel is also known as high-carbon chromium steel. The carbon content Wc is about 1%, and the chromium content Wcr is 0.5%-1.65%. Bearing steel includes six categories: high carbon chromium bearing steel, chromium-free bearing steel, carburized bearing steel, stainless bearing steel, medium and high temperature bearing steel, and antimagnetic bearing steel.

This is the steel of balls, rollers, and bearing rings. And it has a high and uniform hardness, wear resistance, and high elastic limit. The requirements for the uniformity of the chemical composition of this steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are very strict. It is one of the most stringent steel grades in all steel production.

In 1976, the International Organization for Standardization ISO incorporated some general bearing steel numbers into international standards. So the new standard divides the bearing steel into four categories: fully hardened bearing steel, surface hardened bearing steel, stainless bearing steel, high temperature bearing steel, and a total of 17 categories of steel number. Therefore some countries add a category for special purpose bearing steel or alloy.

The classification method of bearing steel that has been included in the standard in my country is similar to that of ISO. Corresponding to the four categories of high-carbon chromium bearing steel, carbon steel, stainless and corrosion-resistant bearing steel, and high-temperature bearing steel.

Performance Requirements of Bearing Steel

In order to meet the above requirements for the performance of dynamic bearings. The following basic performance requirements are proposed for bearing steel materials:

1. High contact fatigue strength;
2. After heat treatment, it should have a high hardness or a hardness because of the performance requirements of the bearing;

3. High wear resistance and low friction coefficient;
4. High elastic limit;
5. Good impact toughness and fracture toughness;
6. Good dimensional stability;
7. Good cold and hot processing performance.

The Difference between Them

In terms of function, there is little difference between stainless steel bearings and bearing steel bearings. Because their main purpose is to use as mechanical transmission parts. However, in terms of performance, stainless steel bearings have more advantages than bearing steel bearings.

(1) Bearing steel generally has a relatively high carbon content to enhance wear resistance. While stainless steel generally has a relatively high Cr content, exceeding 12%. Due to the use of its corrosion resistance.

(2) Compared with ordinary bearings, stainless steel bearings not only have obvious advantages in materials but also have much stricter control over the process and precision than ordinary bearings. So that when in the working process, the stainless steel bearing works stably, with low noise, corrosion resistance, and wide application.

(3) Compared with ordinary bearing steel, stainless steel bearings have stronger anti-rust and anti-corrosion properties. If you choose suitable lubricants, dust caps, etc., that can be used in an environment of -60℃~+300℃. Because of their high mechanical strength and large load capacity, stainless steel bearings are widely used in food processing, medical equipment, and pharmaceutical machinery.