MY125899A - Process and device for producing a ferritically rolled steel strip - Google Patents

Abstract

PROCESS FOR PRODUCING A FERRITICALLY ROLLED STEEL STRIP, IN WHICH LIQUID STEEL IS CAST IN A CONTINUOUS-CASTING MACHINE TO FORM A SLAB AND, UTILIZING THE CASTING HEAT, IS CONVEYED THROUGH A FURNACE DEVICE, UNDERGOES PRELIMINARY ROLLING IN A PRELIMINARY ROLLING DEVICE AND, IN A FINAL ROLLING DEVICE, FINISHING-ROLLED TO FORM THE FERRITIC STEEL STRIP WITH A DESIRED FINAL THICKNESS, IN WHICH PROCESS, IN A COMPLETELY CONTINUOUS, AN ENDLESS OR A SEMI-ENDLESS PROCESS, THE SLAB IS ROLLED IN THE AUSTENITIC RANGE IN THE PRELIMINARY ROLLING DEVICE AND, AFTER ROLLING IN THE AUSTENITIC RANGE, IS COOLED TO A TEMPERATURE AT WHICH THE STEEL HAS A SUBSTANTIALLY FERRITIC STRUCTURE, AND THE STRIP IS ROLLED, IN THE FINAL ROLLING DEVICE, AT SPEEDS WHICH SUBSTANTIALLY CORRESPOND TO THE SPEED AT WHICH IT ENTERS THE FINAL ROLLING DEVICE AND THE FOLLOWING THICKNESS REDUCTION STAGES, AND IN AT LEAST ONE STAND OF THE FINAL ROLLING DEVICE, THE STRIP IS FERRITICALLY ROLLED AT A TEMPERATURE OF BETWEEN 850oC AND 600oC, AND, AFTER LEAVING THE FINAL ROLLING DEVICE, IS COOLED RAPIDLY TO A TEMPERATURE BELOW 500oC IN ORDER SUBSTANTIALLY TO AVOID RECRYSTALLIZATION.FIG 1