METHOD OF PRODUCTION OF LOW-ALLOYED PLATE STEEL Russian patent published in 2004 - IPC

FIELD: metallurgy; rolling; manufacture of thick plates and strips from low-alloyed steel. SUBSTANCE: proposed method includes heating slab to austenizing temperature, roughing for obtaining work-piece of intermediate thickness, cooling-down the work-piece to temperature of 740-760 C, finish rolling at total reduction no less than 30% and temperature of end of rolling not above 740 C. Besides that, at total reduction in the course of finish rolling not exceeding 55% temperature of end of rolling is maintained between 700 and 730 C and at total reduction above 55%, temperature of end of rolling is maintained between 710 and 740 C. Cooling the plate to temperature of 100 C is performed at average rate not exceeding 35 C/h. EFFECT: improved mechanical properties of plate; increased thickness of plate at decreased reduction ratio of slab. 4 cl, 2 tbl, 2 ex