METHOD OF PREVENTING CRACK IN ROLLING CAUSED BY CHANGE OF SET TEMPERATURE OF HEATING FURNACE IN 18-8 STAINLESS STEEL

摘要

PROBLEM TO BE SOLVED: To provide a method of preventing the generation of cracks by changing a hot rolling temperature by properly changing the set temperature of a heating furnace corresponding to the residence time in the heating furnace of a bloom to be heated for hot-rolling 18-8 stainless steel and suppressing the production of ferrite in the corner parts of the bloom in hot rolling.;SOLUTION: When the residence time in the heating furnace for heating in order to the hot-rolling of the bloom of the 18-8 stainless steel is ≥2.5 to 3.5h, the set temperature of the heating furnace is taken as 1,160-1,180°C in the preheating zone, as 1,330-1,350°C in the heating zone and as 1,330-1,340°C in the soaking zone. When the residence time is 3.5-6.0h, the preset temperature is taken as the same as the above in the preheating zone, but as 1,320-1,340°C in the heating zone and as 1,320-1,330°C in the soaking zone. By lowering the each temperature of the heating zone and the soaking zone downward by 10°C as compared with the case where the residence time is 3.5 hr, the cracks in the corner parts of the bloom in the hot rolling are prevented.;COPYRIGHT: (C)2010,JPO&INPIT