Cooling rate is another important factor affecting the performance of 20G steel plate. Due to the large heat storage capacity of the thick plate, the air temperature is low, which has little effect on the cooling rate of the 20G steel plate. The thin plate has small heat storage and fast heat dissipation, and the temperature has a greater influence on its cooling speed. In winter, due to the low temperature, the cooling rate of 20G steel plate is faster, which makes the steel plate mixed crystals seriously, and the shape distribution of pearlite is poor, which will affect the impact toughness of 20G steel plate.
Improve the quality of 20G steel plate in winter
Measures of performance qualification rate In view of the above situation, to improve the performance qualification rate of 20G steel plate in winter, we should focus on improving the performance qualification rate of 12~14mm 20G steel plate. The following suggestions are made:
Raise the finishing temperature
(1) The upper limit should be taken for the rolling temperature of the 20G steel plate less than 16mm, and the lower limit should be taken for the steel plate with a thickness greater than 16mm;
(2) The high-pressure water deoxidation reaction is carried out on the rough rolling mill, and the finish rolling should be carried out in the first three passes of rolling, which is beneficial to increase the final rolling temperature.
Control cooling rate
(1) The cooling water of the 11-roller straightening machine should not be used for 20G steel plate with a thickness less than 16mm;
(2) For 20G steel plates of 12~14mm, stack cooling should be implemented in order to reduce the cooling rate. According to the above steel rolling site suggestions combined with site actual improvement of operation control, the pass rate of 20G steel plate performance has been greatly improved.
Just like you, 70% customers choose long-term cooperation with BBN steel not only for our good product and service quality, good reputation in the international market, but also for our experienced one-stop raw material supply and further steel processing!
