Method of testing gear wheels in impact bending

Chemicothermal treatment processes are widely used in engineering to improve the working lives of important components, of which the most common is nitrocementation. That process has been applied at the Volga Automobile Plant mainly to sprockets in gear transmissions, which need high hardness and wear resistance in the surfaces with relatively ductile cores. Although various forms of chemicothermal treatment are widely used, there has been no universal method of evaluating the strengths of gear wheels. Standard methods of estimating strength (σu, σt, σb, and hardness) have a major shortcoming: They can determine only the characteristics of the cores for case-hardened materials. Here we consider a method of impact bending test, which enables one to evaluate the actual strength of gear teeth.