Black steel is just plain steel. Is in order to increase the corrosion resistance of steel, steel surface with agents for blackening treatment. Generally, steel is processed into a variety of practical tools. After heat treatment, all kinds of fasteners still need to be galvanized or blackened to increase the corrosion resistance of the workpiece.

Residual temperature blackening process is the use of workpiece tempering residual heat blackening. It can not only solve the problem of poor adhesion of blackening film at room temperature, but also achieve the effect of blackening at high temperature by using the residual heat of tempering and reduce energy consumption. It is a new hair black technology which is worth developing and popularizing at present. Iron and steel blackening agent is to use the temper residual heat of the workpiece to form a protective film of black polymer material according to the mechanism of thermal polymerization, so as to achieve the purpose of anti-rust and anti-corrosion.

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