Martensite tempering during fast heating

Modern thermal treatment techniques of fast heating such as passing an electric current through the element, processing by laser beam, electron beam or by high frequency current have been widely used. Frequently such heating is used for the austenitization of hard steel to decrease the austenite grain size before final quenching. However, under slow or fast heating specific low temperature phenomenon of structural heredity occurs when the initial grain of $\gamma$-phase restores in size and form [1]. The detailed description of this phenomenon was made by V. D. Sadovski. Apparently, this phenomenon occurs if bainite is heated above $\mathrm{A_{c1}}$ temperature without considerable tempering. It is obvious that tempering degree depends on the heating rate $V_H$. The paper describes the analytical study of $V_H$ influence on tempering degree with the usage of different models of two-phase martensite decomposition.