BORIDE LAYER GROWTH KINETICS ON X90CrMoV-18 STEEL

Abstract

Boronizing is a type of thermal diffusion with the primary goal of increasing the surface hardness, wear and corrosion resistance. The wear resistance of boronized parts depends on the type of borides that form on the steel surface and their thickness. This study investigated the properties of boride layers formed on X90CrMoV-18 martensitic stainless steel, using pack boronizing carried out in a temperature range of 850–1000 °C and in durations of (1, 3 and 5) h. Results indicate a difference in the boride layer thickness of 3–80 µm and volume share of boride phases depending on the temperature and time of boriding. From the boriding compound depth, values of the frequency factor and activation energy were determined using the Arrhenius equation. With these values, the parabolic equation for predicting the growth rate of a boride layer was formulated and validated for different times and temperatures of boriding.