The bearing foreign material

Abstract: bearing material abroad contacts contact form contact stress in rolling bearing components joints at the heart of the host key host long-term work work location accuracy reliability life largely determine bearing a variety of mechanical motion bearing working environment may be ultra high temperature high temperature caustic soda aqua regia ultra-high vacuum cryogenic corrosion 1. 33 pa may impact abrasive wear of ultra-high speed DMN 2. May thkSBN5012-2 demanding environment 2002:5 screw machine, wto is a challenge but also opportunity experts point out that to strengthen research and development of CNC machine tools in our country to speed up the development of the popular type segment in the machine tool talk at random service competition in the machine tool manufacturing industry in China the status quo of Chinese milling machine and machining center market development direction and prospect of the technology level of domestic and international lathe and machining center production, demand and development trend of world machine tool numerical control system development trend of world development trend both at home and abroad. Rolling bearing parts in the form of point contact and line contact, long-term work under the high alternating should contact stress. Its working parts in the heart of the host or joints, such as to harm. The accuracy, life and reliability of the host to a large extent depends on the bearing. As all kinds of mechanical bearing, bearing working environment may be ultra high temperature (>1000℃) , ultra-low temperature ( - 253℃) , strong corrosion, Acid, alkali, aqua regia and high temperature caustic soda, etc. ) As well as ultra high vacuum ( 1. 33×10 - 9 pa) But it could be a strong shock, strong abrasive wear, non-magnetic and ultra-high speed ( DMN value of 2. More than 2 x 106) And so on. Demanding environment may be single, also might be a mixture of a variety of complex conditions, either common or special bearing, bearing the host for all his life, performance and reliability request high. Many factors that affect the bearing life, including material and heat treatment of the quantity is very large. Bearing structure characteristics and working condition requirements of bearing materials must have high hardness, high wear resistance, high contact fatigue strength, high elastic limit, good impact toughness, good fracture toughness and good dimensional stability, good rust resistance and good heat and cold processing performance, etc. In order to guarantee the performance requirements, quality of bearing steel metallurgy must ensure that the chemical composition of strict, especially high purity ( Low-level non-metallic inclusions) , low oxygen content and residual element content, strict macrostructure and microstructure ( Microscopic) Organization, strict carbide inhomogeneity, strict surface decarburization layer and internal loose, segregation, and microscopic pore requirements; Don't allow there are cracks, slag inclusion, burr, folding, scarring, scale, shrinkage cavity, bubble, since the point and burnt surface and internal defects. In order to ensure the machining performance, the precision of the size of steel also has strict requirements. The quality of bearing steel is the most demanding of all the alloy steel and steel grade of inspection items at most. Recognized in the world, and the level of bearing steel is a sign of a national level of metallurgy. Latest metallurgical technology first commonly used in the development and production of bearing steel. Industrial developed countries in recent decades, with the development and production of the steel bearing applications can be roughly divided into two aspects: on the one hand, the new smelting technology and equipment, or to improve the smelting process and equipment of the traditional, reduce the amount of oxygen content and inclusion in steel, improve the distribution, size and shape of inclusions, improve the crystalline state, etc, to improve the quality of the original steel metallurgy, long service life, pure or ultra clean steel production. On the other hand, the original of the chemical composition of steel to improve or develop new bearing steel, in order to satisfy different use occasion of bearing more and more high performance requirements, or in the same performance under the premise of reduce material cost and the production cost of the bearing.