KOYO import bearing grinding metamorphic layer of the three major factors

The main factors influencing the KOYO import bearing grinding metamorphic layer has two aspects, respectively is a function of bearing grinding forces and grinding heat. 1, the grinding force in grinding process, the workpiece surface layer will be grinding wheel cutting force, compression force and friction force. And, in particular, the role of the latter two, make the workpiece surface layer formed directional strong plastic deformation and strain hardening layer. The metamorphic layer is bound to affect the surface residual stress changes. ( 1) Cold plastic deformation layer in the process of grinding, every moment of abrasive is equivalent to a cutting edge. But in many cases, the rake Angle of cutting edge negative, in addition to abrasive cutting action, is to make the workpiece surface under compression ( The plough) That left obvious plastic deformation of workpiece surface layer. The deformation layer deformation degree as the degree of grinding wheel dull increases and grinding feed. ( 2) Thermoplastic deformation ( Or high temperature deformation) Layer of grinding heat in the transient temperature of the work surface formation, makes a certain depth of the workpiece surface layer elastic limit fell sharply, even to the point of elastic disappear. The work surface on the grinding force, especially under the action of compression force and friction force, caused by free stretch, subject to the conditions of the matrix metal, the surface is compressed ( More plough) , cause the plastic deformation in the surface layer. High temperature plastic deformation under the condition of the grinding process is constant, with the temperature increasing of workpiece surface. ( 3) Sometimes work hardening layer microhardness and metallographic method can be found that caused by the machining deformation of surface hardness. 2, grinding heat in the grinding, grinding wheel and workpiece contact zone, consume large amounts of energy, produced a large number of grinding heat, local transient high temperature caused by grinding area. On the basis of the theory of linear motion heat source heat transfer formula derivation, calculation or by the method of infrared ray and measured experiment under the condition of instantaneous temperature thermocouple method, can be found in 0. 1 to 0. The grinding area within 001 ms instantaneous temperature up to 1000 ~ 1500 ℃. The instantaneous high temperature, which would have made certain depth on the surface of the work surface to produce high temperature oxidation, amorphous group, high temperature tempering, secondary hardening, and even burn cracking and other changes. Proper material selection is still is KOYO import bearing failure analysis factors must be considered. The main task of the bearing failure analysis, which is based on a lot of background material, analyze data and failure forms, find out the main factors of bearing failure, so that the improvement measures are put forward, prolonging bearing, avoid premature failure of the bearing of the sudden. Installation conditions is one of the primary factor of use factor, bearing is often caused by improper installation of a complete set of change the stress of bearing between various parts, bearing in the abnormal state run and early failure. According to the bearing installation, use, maintenance, maintenance of technical requirements, KOYO import bearings in operation on the load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, found that abnormal immediately to find the reason, adjustment, so that it is back to normal. First of all, reasonable structure design and equipped with advanced, just can have a long bearing life. Bearing manufacturing generally go through forging, heat treatment, cutting, grinding and assembly, and multi-channel processing operations. The rationality of the processing technology, advanced, stability will also affect the service life of bearing. Which affects the quality of finished products bearing heat treatment and grinding process, tend to have a more direct relationship with bearing failure. Bearing in recent years the study of metamorphic layer of bearings working surface show that the grinding process and is close to the surface quality of the bearing. Bearing materials of metallurgical quality were the main factors influencing the premature failure of the rolling bearing. As metallurgy technology, For example, the bearing steel vacuum degassing, etc. ) Progress, raw material quality is improved. Raw material quality factor in the bearing failure analysis share has declined obviously, KOYO import bearings but it is still one of the main influence factors of bearing failure.