a method of hot rolling of ferritic-austenitic duplex stainless steel to prevent edge crack

摘要

PURPOSE: A method for hot rolling a duplex stainless steel for preventing edge crack is provided to settle process load in the subsequent process and increase actual yield by effectively restraining generation of edge crack in the finish milling process without hindrance of corrosion resistance and ductility at an ordinary temperature of steel when manufacturing hot rolled strip by hot rolling the duplex stainless steel. CONSTITUTION: In a method for manufacturing a hot rolled strip comprising the processes of manufacturing a slab by continuous casting duplex stainless steel; and passing the heated slab through rough rolling and finish milling after heating the slab in a reheating furnace, and then extracting the slab, the method for hot rolling a duplex stainless steel for preventing edge crack is characterized in that the hot rolled strip is manufactured by passing the rough rolled slab through finish milling after rough rolling the heated slab by controlling a reduction ratio per pass to less than 20%, and a rough rolling finishing temperature to 1020 deg.C or more in the rough rolling process, wherein the finish milling is performed after homogenizing the temperature distribution in a width direction of a rolled sheet by maintaining the transferred bar on transferring rollers for 30 to 60 seconds right before finish milling the bar after passing a rough rolling completed transferred bar through an edge heater.