Thermodynamic aspects of electron-beam surface modification of low-carbon steel

Multicomponent surface modification of carbon steels is of high interest in mechanical engineering due to its beneficial impact on machine components’ and structures’ surface properties. The present research was devoted to simulating the process of aluminides and borides formation on the surface of low-carbon steel during electron beam alloying and predict the phase composition of the obtained coatings. Computational thermodynamics and approximate calculation method were used to solve the problem mentioned above. Calculations were done in the temperature range between 200 and 2000 K at 10 −3 Pa. It was discovered that the calculated and experimental data of the coating’s phase composition differs significantly. The only confirmed phase that was predicted by the calculations was sodium fluoride (NaF). It was established that NaF presence in the treatment paste was redundant for the electron beam alloying because of its low reactivity in a vacuum. XRD analysis revealed the following phases in the coating: Fe 2 B, Fe 3 C, and AlFe 3 .