HIGH STRENGTH AUSTENITIC STAINLESS STEEL HAVING SUPERIOR CORROSION RESISTANCE AND WEATHERABILITY AND METHOD FOR MANUFACTURING STEEL SHEET USING THE SAME

摘要

PURPOSE: An austenitic stainless steel for improving corrosion resistance and strength at low cost by adding N instead of expensive Cr and Mo and further improving strength by reducing inclusions that become a starting point of corrosion is provided, and a method for manufacturing steel sheet using the same is provided. CONSTITUTION: The method for manufacturing high strength austenitic stainless steel sheet having superior corrosion resistance and weatherability comprises a step of manufacturing a hot rolled strip by hot rolling the heated steel slab after heating a steel slab comprising 0.07 wt.% or less of C, 1.0 wt.% or less of Si, 2.0 wt.% or less of Mn, 18 to 20 wt.% of Cr, 7 to 10 wt.% of Ni, 0.005 wt.% or less of Al, 0.05 wt.% or less of P, 0.01 wt.% or less of S, 0.03 wt.% or less of Ti, 0.003 wt.% or less of B, 0.1 to 0.25 wt.% of N and a balance of Fe and other inevitable impurities in the temperature range of 1,230 to 1,300 deg.C for 200 to 240 minutes; a step of hot annealing the hot rolled strip at an atmospheric temperature of 1,130 to 1,170 deg.C; and a step of manufacturing a cold rolled strip by cold rolling the hot annealed strip, cold annealing the cold rolled strip at an atmospheric temperature of 1,130 to 1,170 deg.C, and pickling and skin pass rolling the cold annealed strip.