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The paper presents the results of investigations concerning
the hot plastic deformation of HSLA steel (0,16%C, 1,48%Mn, 0,037%Nb, 0,004%Ti, 0,0098%N), particularly the kinetics of static thermally activated
processes. The results of softening kinetics have been gathered in RTT diagrams (Recrystallization, Temperature, Time). Besides that the samples
were metallographically observed using a light and electron microscope (TEM). The tests were carried out on samples previously cooled down immediately
after their deformation and relaxation. It has been found that in the course of isothermal holding of the steel there occurs a recovery and static
and metadynamic recrystallization. The kinetics of these processes depend mainly on the temperature and degree of deformation of the steel. An essential
refi nement of the prior size of the austenite grains was detected at the temperature of deformation amounting to 900 °C and the strain ε in the
range from 0,4 to 0,6.
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