The main mechanism of grinding wheel burns introduction

When the grinding wheel surface temperature , if the cooling measures is not good , it's easy on the workpiece surface ( from tens to hundreds of um um) occur secondary quenching and tempering . If the grinding wheel surface layer of the instant temperature exceeds steels AC1 point, the role of the secondary coolant quenched martensite , while  concrete saw blades in the subsurface due to temperature gradients , short time , only the formation of high-temperature tempering organization This makes the surface and subsurface between the tensile stress and the surface of a thin brittle secondary hardening martensitic , when can not afford , it will crack.
Heat treatment of
A ) residual austenite retained austenite grinding wheel grinding wheel grinding wheel because heat and pressure generated changes occur at the same time may be accompanied by tempering and grinding wheel surface cracks. Amount of residual austenite should be controlled within 30% .
2 ) carbon concentration diffusion layer nitrided layer carbon concentration is too high, easy to form a nitrided layer tissue or excessive free mesh carbide carbide . Because this substance extremely hard , the wheel grinding process may lead to local overheating tendencies and incidence surface tempering . Nitrided layer carbon concentration is too high, the surface will produce excessive residual austenite. Resulting in burns and cracks. Therefore, the surface carbon concentration increases, reducing the performance of the grinding wheel , the general surface carbon concentration should be controlled within the range of 0.75% -0.95 % .
3 ) carbide distribution should be diamond core drills  uniform carbide distribution and morphology , particle size not greater than the average diameter lμm; carbide morphology should be spherical , powdered or finely punctate distribution along the net , mesh or angular carbides are not allowed .
4 ) decarburization heat treatment . Surface or environmental cause improper surface oxidation , so that the workpiece will produce a thin carbon layer , this layer will cause decarburization soft wheel overload or overheating , resulting in surface tempering .
5 ) tempering the premise of ensuring the hardness , the tempering temperature is as high as possible a number , as long as some of the annealing time . This can improve the surface carburized hardened plastic , and the residual stresses are balanced or lower . Improving the abrasive tools  distribution of surface stress . This can reduce the probability of cracks occur workpiece , thereby improving the efficiency of the grinding wheel grinds the workpiece .
6 ) deformation should minimize heat deformation . This reduces the grinding wheel margin. If the heat deformation is too large, if the operation is not in the workpiece grinding wheel radial runout maximum at the beginning of the grinding wheel , grinding wheel each time point at which the grinding wheel is removed margin would not be normal, resulting in burns and cracks.