Basic Requirements for the Quality of NTN Bearing Steel
Source: China Bearing Network | Time: 2014-01-25
The performance and reliability of NTN bearings are heavily dependent on the quality of the bearing steel used. Unlike ordinary industrial steel, NTN bearing steel must meet much stricter standards in terms of chemical composition, purity, structure, and uniformity. These requirements ensure that the bearings can withstand high loads, maintain precision, and operate smoothly over long periods. Firstly, the chemical composition of NTN bearing steel must be strictly controlled. It is primarily a high-carbon chromium steel, with carbon content around 1% and chromium content about 1.5%. Small amounts of manganese and silicon are also present. Chromium enhances heat treatment properties, improves hardenability, and increases wear resistance. However, if the chromium content exceeds 1.65%, it may lead to retained austenite, which reduces hardness and dimensional stability. Therefore, chromium levels are usually kept below 1.65% to ensure optimal performance. Secondly, the dimensional accuracy of the steel is crucial. Since most NTN bearing components are formed through pressure processing, any deviation in size can affect the final product’s quality. Proper control of dimensions ensures accurate machining and avoids damage to tools and molds during production. Thirdly, the purity of the steel is essential. Non-metallic inclusions such as oxides and silicates can significantly reduce the lifespan of bearings by causing early failure. The presence of brittle inclusions can damage the surface finish of the bearing parts, making it vital to minimize these impurities. Fourthly, the microstructure of NTN bearing steel must be uniform. Both low- and high-magnification structures, including carbide distribution and annealing patterns, play a critical role in the mechanical properties of the steel. Any irregularities can lead to reduced fatigue strength and potential cracking during heat treatment. Fifthly, external and internal defects must be minimized. Cracks, slag inclusions, oxide scales, shrinkage cavities, and segregation can all compromise the integrity of the bearing. These flaws are strictly prohibited in the NTN bearing steel specifications. Sixthly, carbide distribution must be even. Uneven carbide formation can cause hardness variations and weaken the material’s structural integrity, leading to premature failure. Lastly, the decarburization layer on the surface of the steel must be carefully controlled. If not removed before heat treatment, it can result in quenching cracks and invalid parts. In addition to these, there are strict requirements regarding the manufacturing process, oxygen content, annealing hardness, fracture analysis, residual elements, spark testing, delivery conditions, and labeling of NTN bearing steel. For more information on bearings and related technologies, you can explore other articles such as "The Impact of Temperature on INA Bearings" or "How to Choose the Right Centering Bearing." This article was originally published on China Bearing Network. For more details, visit China Bearing Network. Previous: INA Deep Groove Ball Bearing Next: Wheel Bearing Equipment and Application Knowledge
We are a professional engineering company specialized in music fountains, indoor and outdoor waterscape, all kinds of music fountains lighting shows, digital water curtains, and water screen movies.Our company has strong design force and technical installation force, and wholeheartedly provides customers with integrated services from scheme design, equipment production to equipment installation and debugging, music program programming and editing and directing services.The shape of funny fountain is strange and it can show many different scenes.
Funny Fountain,Dance Fountain,Jumping Fountains,Dancing Water Fountain
Wuxi Jinshanghua Environmental Equipment Co., Ltd , https://www.jshfountain.com