1.The mechanical impact load of the high speed big passenger and large tonnage truck brake is very large. If there is not enough strength, it will be very dangerous when the brake drum breaks down when the brake is not enough. So we select the tensile strength of the high speed large passenger and heavy load brake drum at the normal temperature of 200-250MPa.

    2.The brake drum requires good thermal conductivity, the thermal energy converted into the brake energy is sent out in time to maintain the stability of the tissue. In the pearlite matrix gray cast iron, the highest heat conduction velocity is flaky graphite. The thermal conductivity of the brake drum is proportional to the graphite and the graphite length, in order to improve the thermal conductivity of the brake drum. The amount of graphite and the length of graphite must be increased.

    3.Because the fatigue cracking of the grey cast iron brake drum has a direct relationship with the change of the tissue, it is necessary to improve the stability of the brake drum structure, especially at high temperature, and less or no phase change. The gray cast iron brake drum must have a high strength limit, and its matrix is only the pearlite matrix or pearlite and a small amount of ferrite. Therefore, a certain alloying element must be added to stabilize the pearlite and maintain its high temperature structure stability.