Advantages of Bearing Steel as a Raw Material for Bearing Manufacturing

Characteristics of bearing material bearing steel:

1、 Contact fatigue strength

Under the action of periodic loads, bearings are prone to fatigue damage on the contact surface, resulting in cracking and peeling, which is an important damage situation for bearings. Therefore, in order to improve the service life of bearings, bearing steel must have high contact fatigue strength.

2、 Wear resistance

During the bearing task, not only rolling friction occurs between the ring, rolling element, and maintenance bracket, but also sliding friction, resulting in continuous wear of the bearing parts. In order to increase the wear of bearing parts, maintain bearing accuracy and stability, and extend service life, bearing steel should have good wear resistance.

3、 Hardness

Hardness is one of the important qualities of bearing quality, which indirectly affects contact fatigue strength, wear resistance, and elastic limit. The hardness of bearing steel under operating conditions should reach HRC61~65, which enables the bearing to achieve high contact fatigue strength and wear resistance.

4、 Rust prevention performance

In order to avoid corrosion and rusting of self-aligning roller bearing parts and finished products during processing, storage, and use, it is requested that bearing steel should have good rust prevention performance.

5、 Processing performance

In the consumption process of bearing parts, there are many cold and hot processing processes. In order to meet the requirements of small quantities, high efficiency, and high quality, bearing steel should have good processing performance. For example, cold and hot forming performance, cutting performance, hardenability, etc.

In addition to the basic requirements mentioned above, bearing steel should also meet the requirements of appropriate chemical composition, average external structure, less non-metallic impurities, compliance with specifications for external surface defects, and non exceeding the regular concentration of decarburization layer on the surface.

Monitoring of bearing working status and material performance requirements

1. Morphological characteristics of wear particles under normal conditions

During the running in period and normal operation period of the bearing, the size of the abrasive fragments generated is generally 0.01-0.015mm, mixed with some metal powder. The number of abrasive fragments generated by the new bearing during the running in period is higher than that during the normal operation period. After entering the normal operation period, the number of abrasive fragments and metal powder will significantly decrease. The abrasive fragments present a thin and short shape under a microscope, with irregular cross-sections.

2. Morphological characteristics of faulty wear particles

The main failure form of self-aligning roller bearings is fatigue pitting. The size of abrasive fragments formed by rolling fatigue and peeling is generally 0.025-0.05mm. Sometimes there are larger fragments mixed with some metal powder. The steel ball abrasive fragments of ball bearings usually appear in the form of roughly circular, radially separated rose petals; The abrasive debris in the raceway presents a roughly circular surface fragmentation form; The grinding debris of roller bearings usually presents in a rectangular shape with a length equal to 2-3 times the width of the curl; The abrasive debris in the raceway generally presents an irregular rectangular shape.

The design of the bearing combination structure includes the following items

The design of the bearing combination structure includes the following items:

1. Shafting support end structure

(1) To ensure that the rolling bearing shaft system can transmit axial force normally and does not move, it is necessary to design the axial fixed structure of the shaft support points reasonably based on the positioning and fixation of the components on the shaft.

(2) When the shaft is long or the working temperature is high, the thermal expansion and contraction of the shaft are relatively large. It is advisable to use a pivot structure with one end fixed in both directions and one end movable.

(3) Shafts that require bidirectional movement can adopt a shaft system structure with both ends moving.

2. Matching between bearings and related parts

The purpose of the fit between the bearing and the shaft or bearing seat is to firmly fix the inner and outer rings on the shaft and bearing seat, so that they do not slide harmful to each other. If the mating surface slides, abnormal heating and wear will occur, as well as early damage and vibration caused by powder entering the bearing due to wear, resulting in the bearing not fully functioning. In addition, the fit of the bearing can affect the radial clearance of the bearing, which not only affects the operating accuracy of the bearing, but also affects its lifespan.

3. The stiffness and coaxiality of the bearing seat

The shaft and bearing seat must have sufficient stiffness to avoid uneven force on the rolling element due to excessive deformation. Therefore, the bearing seat hole wall should have sufficient thickness and reinforcement ribs should be often set to increase stiffness. In addition, the cantilever of the bearing seat should be as short as possible.

4. Lubrication and sealing

The lubrication of self-aligning roller bearings is mainly to reduce friction resistance and reduce wear, while also having functions such as vibration absorption, cooling, rust prevention, and sealing. Reasonable lubrication is of great significance for improving bearing performance and extending the service life of bearings. In order to fully utilize the performance of the bearing, it is necessary to prevent the leakage of grease or oil in the lubricant, and also to prevent harmful foreign objects from entering the bearing from the outside. Therefore, it is necessary to use a complete seal as much as possible.