Effect of thermal-cyclic deformation and heat treatment on the structure and electrical properties of Ст3
The results of the effect of preliminary thermal-cyclic deformation on the microstructure of hot-rolled low-carbon steel Ст3пс are presented. It is shown that the regime of thermal-cyclic rolling leads to a decrease in the average grain size of ferrite from 8 to 6 microns in comparison with the structure of steel after industrial production. There is a decrease in the size of pearlite colonies and their volume fraction in the structure of steel after using thermal-cyclic deformation. The results of the effect of heat treatment: normalization and tempering on the electrical resistivity of the hot-rolled carbon steel sheet Ст3пс produced using thermal-cyclic mode of deformation processing (DTCT). DTCT preliminary thermal-cyclic was rolled (5 cycles at a reduction of 10-15 % in each cycle and cooled to a temperature below the Ar1). And normalizing annealing was carried out in the range from 100 to 900 °C increments to 100 °C for 1 hour. The possibility to reduce the magnitude of the specific electrical resistance of the hot-rolled steel manufactured using DTCT mode through the use of subsequent normalizing at 700 °C on average 10 %, and by annealing – no more than 5 %. A further increase in the time of normalization at 700 °C to 3, 5 and 10 hours has no significant effect on the value of the electrical resistance of the steel subjected DTCT. However, the downward trend in resistivity is maintained. Overall reduction of electrical resistivity of the hot-rolled steel Ст3пс by using
mode DTCT and subsequent normalizing at 700 °C for 1 hour is more than 12 %.