Nmb bearing steel heat treatment technology

Nmb bearings Nmb bearing steel heat treatment technology is usually used to support the rotation of the shaft neck and shaft parts, usually by the inner ring and outer ring, rolling body ( Ball bearings, roller, roller cone or needle) And maintain, etc. Used in the manufacture of Nmb bearing steel, known as Nmb bearing steel. Nmb bearing steel: Nmb bearings, machine load between the rotating part and fixed part by rolling pass. In theory, between race and rolling elements to point ( Or line) Contact, under concentrated load, usually contact stress is as high as 1500 - - - 5000MPa。 When the bearing is running, each point under compression bearing a tensile cyclic load, maximum force by zero, by maximum to zero again, the periodic increase and decrease, and a great cycles ( Generally up to tens of thousands of times/min) 。 Circle of roll body were present in addition to the rolling, and the relative sliding, thus produce rolling friction and sliding friction. In some cases, the bearing will be impacted by the complex torque or certain. So, Nmb bearings is the main damage form contact fatigue damage ( How to pitting and spalling) And wear. To bearing can work normally, not early failure, must have high hard R (Nmb bearing More than 69 HRC) And high wear resistance; With high compressive strength and contact fatigue strength; Good dimensional stability and corrosion resistance. For bearing used in specific situations, should also has high heat resistance, corrosion resistance, etc. Chromium bearing steel is make Nmb bearing parts, as well as with the bearings Nmb parts working conditions similar to those of other parts used by the main steel grade, one of the biggest amount of GCr15 steel, followed by GCr15SiMn. Chromium bearing steel carbon mass fraction is 0. 95% - 1. 05%, high carbon content of steel after quenching with high strength, hardness and wear resistance. Chromium can improve the hardenability of steel. In carbon mass fraction of 1% hypereutectoid steel, chromium can dramatically improve the distribution of carbide and grain size in steel. Chromium bearing steel after quenching and tempering, has good wear resistance, strength, yield strength and elastic limit. The mass fraction of chromium bearing steel, manganese to. 0. A 1 9%. Increased 2%, mass fraction of silicon to 0. 40% - 0. 70%, with the composition of steel, such as GCr9SiMn and GCr15SiMn, the hardenability, tempering resistance and strength were increased, and the toughness is not down.