Coiling Temperature Optimization of Hot-Rolled X80M Pipeline Steel Plate

An X80M pipeline steel plate with specification of 18.4 mm×1 550 mm was coiled at different coiling temperatures of 300, 350, 400, 450℃, respectively. The control stability of the coiling temperature and the microstructure and mechanical properties of the coiled steel plate were studied. The coiling temperature was optimized. The results show that the stability of the measured coiling temperatures increased with the coiling temperature rising. The microstructure of the tested steel consisted of acicular ferrite after coiling at 300-450℃; the mechanical properties met the technical requirements, with a certain allowance of both strength and low-temperature toughness. The optimal coiling temperature was 380℃. The tested steel coiled at this temperature had good mechanical properties.