METHOD FOR REDUCING RESIDUAL STRESS OF LARGE-SIZED HOLLOW CAST ROLL MADE OF STAINLESS

摘要

PURPOSE:To reduce the residual tensile stress of a hollow cast roll without requiring annealing by subjecting a thick-walled and large-diameter hollow cast roll made of stainless steel to solution heat treatment for the purpose of improving corrosion resistance and then applying cooling to the internal surface of the hollow part of the above hollow cast roll by means of mist-containing air under specific conditions. CONSTITUTION:In order to improve the corrosion resistance of a thick-walled, large- diameter, and long-size hollow cast roll 1 made of stainless steel, the above hollow roll 1 is heated, e.g. to 1000-1200 deg.C and successively subjected to forced cooling to undergo solution heat treatment. Subsequently, the above hollow roll 1 is subjected to forced cooling by supplying moist air containing mist by 0.01-0.03l per cubic meter of air through the temp. range from the solution heat-treating temp. down to 300 deg.C from a duct 4 with a water nozzle 6 at the inlet of one end of the hollow roll 1 by means of the high-speed rotation of a fan 3 by a motor 2 at a rate of 1200-2400sm3 [(s) means the cross-sectional area (m2) of the hollow part of the roll 1] per minute, by which tensile residual stress can be reduced without requiring annealing treatment and the occurrence of defects during use, such as breakage, can be prevented.