Martensite Tempering during Fast Heating

Abstract

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 γ-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 Ac1 temperature without considerable tempering. It is obvious that tempering degree depends on the heating rate VH. The paper describes the analytical study of VH influence on tempering degree with the usage of different models of two-phase martensite decomposition