Fig. 3

Raster image of a surface of reverted austenite after 100 γ-α-γ transformations with fast heating and one γ-α-γ transformation with slow heating at the interval of α-γ transformation. Special structural state of the reverted austenite is formed in the process of the multiple reverse diffusionless α-γ transformations and following α-γ transformation controlled by diffusion mechanism. Slow heating of the quenched alloy (at the rate of less than 2 °C/s in the interval of the reverse α-γ transformation), which exhibits nanofragmented austenite structure formed during previous 100 γ-α-γ transformations, resulted in the nanograin refinement by multiplication of orientations in the reverted γ phase. The special structural state formed after such a combined treatment, i.e., by using diffusion and diffusionless α-γ transformations, can be characterized by absence of typical for the reverse transformation relief. Instead, the features of plastic deformation of the reverted austenite are seen in figure