INFLUENCE OF THERMAL CYCLE OF SURFACING ON MECHANICAL PROPERTIES AND RESISTANCE OF HAZ METAL OF RAIL STEEL M76 TO BRITTLE FRACTURE

摘要

Increasing the life of railway wheels is an urgent problem. The solution to this problem is associated with the optimization of the structural state of metal of railway wheels. In the work the influence of cooling rate during melting on mechanical properties, resistance to brittle fracture and structural changes of the HAZ metal of wheel steel with carbonitride strengthening with a carbon content of 0.63% were investigated. It is shown that in the process of surfacing, a hardening bainite-martensitic structure is formed, the volume fraction of structural components in which is determined by the cooling rate. The hardened HAZ metal of wheel steel with carbonitride strengthening has a high strength and a low ductility with a high susceptibility to brittle fracture. 12 Ref., 2 Tables, 11 Figures.