Principle of the shift of the temperature of the instrumental onset of the austenite transformation in steels during high-speed and laser heating

It is shown that the shift of the temperature of the onset of the austenitic transformation in steels during high-speed heating can be interpreted as a time delay of the α→γ transformation relative to the rate of change of temperature. During heating of steels with laser radiation pulses the temperature shift may be considerable and this restricts the range of temperatures in which steels can be hardened without melting and can reduce the hardening efficiency. The calculated and experimental temperatures agree satisfactorily.