Grinding Cracks

Shallow cracks formed on the surface of relatively hard materials due to excessive grinding heat to allotropic transformation of the surface material, or to the high sensitivity of the material surface containing high tensile residual stresses.

Grinding cracks typically are at 90° to the direction of grinding. They are perpendicular to the component surface, have sharp edges and can propagate under cyclic loading.

Over heating can be caused by using the wrong grinding wheel, a dull or glazed wheel, insufficient or poor coolant, feeding too rapidly or cutting too heavily.