During grinding, due to the thin metal layer being cut, less chips are generated, and the thermal conductivity of the grinding wheel is poor, so less than 10% of the heat can be taken away by the chips, and about 60% and 90% of the heat is transferred to The parts are gathered on the surface of the parts in a very short time to form a local high temperature, so that the temperature in the grinding area can reach 8001000 ° C, or even higher, and then a great temperature gradient is formed on the surface of the parts. On the other hand, the temperature of the surface of the part rises sharply during the operation until it finally cools down, and the thermal expansion and contraction of the surface of the part causes residual stress from the surface to the interior of the part.
If grinding burns occur in rotating parts, such as steering knuckles, transmission shafts, valve stems, camshafts, crankshafts, valves, bearings, gears and other parts, most of these parts are in an alternating load working environment. Under the action, the few fine lines appearing on the surface of the part develop into a network of cracks that expand and connect to each other into pieces, eventually causing the surface of the part to peel off.
