How To Improve Bearing Steel Quality

 

According to the analysis of the effects on the quality of bearing steel, we can improve the quality of bearing steel by improving the dimensional accuracy and surface quality, purity and uniformity of bearing steel.

 

1. Improve the dimensional accuracy and surface quality of bearing steel

1) Improve the dimensional accuracy of bearing steel:

• Optimize the production process: reduce variables and errors in production through refined process design.
• Improve lathe accuracy: Use high-precision lathes for processing to ensure accurate dimensions of bearing steel parts.
• Regular calibration and maintenance of equipment: Regular calibration and maintenance of production equipment such as lathes and cutting tools to maintain the stability of their accuracy.
• Implement strict inspection processes: Implement strict dimensional inspections in all aspects of production to ensure that the dimensional accuracy of bearing steel parts meets requirements.

2) Improve the surface quality of bearing steel:

•  Strengthen basic grinding processing: remove burrs, cracks, rust and other defects on the steel surface through high-precision grinding and polishing processes.
•  Surface cleaning treatment: After grinding and polishing, perform surface cleaning treatment to remove residual grinding fluid, oil stains and other impurities.
•  Heat treatment process optimization: By accurately controlling the heat treatment temperature and time, the microstructure of the steel is adjusted to improve the hardness and wear resistance of the steel.
•  Surface carburizing treatment: According to needs, surface carburizing treatment is performed to increase the carbon content on the surface of the steel and improve the surface hardness and wear resistance.
•  Using advanced surface coating technology: such as PVD, CVD and other coating technologies, a hard coating is formed on the surface of the steel to improve surface quality and service life.

 

2. Improve the purity of bearing steel

1) Control the oxygen content in the bearing steel:

• Choose appropriate raw materials: Choose steel, ferrochrome and other raw materials with low oxygen content to fundamentally reduce the oxygen content.
• Optimize the smelting process: Use high-quality smelting equipment and processes, increase the furnace temperature and stirring frequency, and ensure a fully uniform smelting process to reduce oxygen inhalation.
• Strict composition control: Through chemical composition detection, composition control before heat treatment is achieved to ensure that the oxygen content in the steel is within a controllable range.

2) Reduce the inclusion content in bearing steel:

Choose the right deoxidizer:

• Aluminum deoxidation: Final deoxidation with aluminum can reduce the oxygen content in the steel and obtain an appropriate amount of acid-soluble aluminum. However, attention needs to be paid to controlling the content of acid-soluble aluminum to avoid being too high or too low.
• Barium deoxidation: Barium is an ideal deoxidation modifier. Barium alloy not only has strong deoxidation ability, but also can denature residual inclusions in steel very well.
• Magnesium deoxidation: Magnesium has a significant effect on the deterioration of Al2O3 inclusions in bearing steel and can further reduce the content of inclusions.

Optimize the smelting process:

• Vacuum melting: Melting in a vacuum environment can effectively remove gases and inclusions in steel.
• Electroslag refining: Through the electroslag refining process, non-metallic impurities in steel are further removed and the purity is improved.

3) Reduce the carbide content in bearing steel:

• Controlling primary liquid precipitation carbides: Reduce the formation of primary liquid precipitation carbides by optimizing the smelting process and composition control.
• Eliminate or reduce secondary network carbides: For hypereutectoid steel, the formation of secondary network carbides can be eliminated or reduced through controlled rolling, controlled cooling or low-temperature rolling processes.
• Control of tertiary eutectoid carbides: Through processes such as spheroidization, the particles of tertiary eutectoid carbides are made fine and evenly distributed to reduce the impact on performance.

 

3. Improve the uniformity of bearing steel

1) Application of controlled rolling and controlled cooling process:

Controlled rolling and controlled cooling is to improve the strength, toughness, welding performance, etc. of steel by controlling heating temperature, rolling process, cooling conditions and other process parameters during the rolling process.

Applying controlled rolling and controlled cooling technology to bearing steel can greatly improve the overall performance of the steel, reduce and eliminate liquid precipitation, network and band carbides, reduce the average size and maximum particle size, and reduce and suppress network carbides. ‘s appearance.

By precisely controlling the rolling temperature and cooling rate, the uniformity of the internal structure of the steel is achieved, and the mechanical properties and service life of the bearing steel are improved.

2) Improve the grain size of the matrix structure:

Grain size refers to the size and arrangement of crystals in metal materials. The smaller the grain size, the tighter the crystal arrangement, and the strength and hardness of the material also increase accordingly.

In the manufacturing process of bearing steel, the grain size of the matrix structure can be further improved by optimizing the heat treatment process, such as increasing the heating temperature and extending the holding time, so as to further refine the grain size of the bearing steel.

Refined grains can significantly increase the strength and toughness of bearing steel, while improving the material’s wear resistance and fatigue resistance.

3) High temperature spheroidizing annealing treatment:

High-temperature spheroidizing annealing is a heat treatment process that heats steel to a certain temperature, holds it for a certain period of time and then slowly cools it.

For hypereutectoid bearing steel, high-temperature spheroidizing annealing can eliminate network carbides and achieve refinement and uniformity of carbides.

Through high-temperature spheroidizing annealing treatment, the carbide particles inside the bearing steel can be made finer and more uniform, thereby improving the mechanical properties and service life of the material.