Effect of the temperature of megaplastic deformation on the redistribution of carbon in Fe–Ni–C austenite

Structural phase transitions induced by megaplastic deformation at temperatures of 80–573 K are investigated in high-carbon Fe–Ni austenite of the invar range of compositions. Phase transformations change their direction from the nonequilibrium dissolution of graphite particles upon low-temperature (80 and 293 K) deformation and the activation of carbon precipitation from the fcc matrix to graphite upon high-temperature (373–573 K) deformation, due to the structure being saturated with point defects.