Improving the technology of chemical-thermal treatment of tool steels

Abstract

The paper presents data on the study of the intensification of chemical-thermal treatment processes. Diffusion saturation of the surface of steels and alloys is most often carried out under high-temperature isothermal or isothermal-step exposure with complete recrystallization of steel into an austenitic state. This leads to overheating — the structure and mechanical properties, in addition to hardness and wear resistance, deteriorate. the main regularities and mechanisms of boration of ferritoperlite steels are investigated and described. It is shown that cyclic heating and cooling significantly accelerate the kinetics of the CTO process of iron-carbon alloys. It was found that thermal cycling during boration leads to an increase in the layer thickness up to 80% on carbon steels, with an increase in the degree of alloying, the effect decreases from 70% (cast steel 5KHNM) to 20% (steel X12M). With an increase in the carbon content in steel, the depth of the borated layer decreases both after isothermal high-temperature boration and after thermocyclic boration.