Induction heatable stainless steel sheet having excellent corrosion resistance and method of manufacturing the same

Abstract

A stainless steel sheet for cookware and a method of manufacturing the same and, particularly, an induction heatable stainless steel sheet having excellent corrosion resistance and a method of manufacturing the same are provided. The induction heatable stainless steel sheet having excellent corrosion resistance includes, by wt %, C: 0.1% or less (excepting 0%), Si: 0.2% to 3.0%, Mn: 1.0% to 4.0%, Cr: 19.0% to 23.0%, Ni: 0.3% to 2.5%, N: 0.18% to 0.3%, Cu: 0.3% to 2.5%, iron (Fe) as a residual component thereof, and other unavoidable impurities, and has relative permeability of 20μ r to 80μ r . In addition, a microstructure includes, by volume %, ferrite: 30% to 70% and austenite as a remainder thereof.

1 . An induction heatable stainless steel sheet having excellent corrosion resistance comprising, by wt %, carbon (C): 0.1% or less (excepting 0%), silicon (Si): 0.2% to 3.0%, manganese (Mn): 1.0% to 4.0%, chromium (Cr): 19.0% to 23.0%, nickel (Ni): 0.3% to 2.5%, nitrogen (N): 0.18% to 0.3%, copper (Cu): 0.3% to 2.5%, iron (Fe) as a residual component thereof, and other unavoidable impurities, and
 having relative permeability of 20μ r  to 80μ r ,   wherein a microstructure includes, by volume %, ferrite: 30% to 70% and austenite as a remainder thereof.   
     
     
         2 . The induction heatable stainless steel sheet having excellent corrosion resistance of  claim 1 , wherein Md30, where Md30=551−462×(C %+N %)−9.2×Si %−8.1×Mn %−29×(Ni %+Cu %)−13.7×Cr %−18.5× Mo %−68×Al %, of the stainless steel sheet is 80 or less. 
     
     
         3 . The induction heatable stainless steel sheet having excellent corrosion resistance of  claim 1 , wherein elongation of the stainless steel sheet is 40% or more. 
     
     
         4 . The induction heatable stainless steel sheet having excellent corrosion resistance of  claim 1 , wherein pitting potential of the stainless steel sheet is 280 mV or more. 
     
     
         5 . The induction heatable stainless steel sheet having excellent corrosion resistance of  claim 1 , wherein cookware formed of the stainless steel sheet heats water to boiling point within 10 minutes when 500 cc of water at room temperature is heated by an induction heater. 
     
     
         6 . A method of manufacturing an induction heatable stainless steel sheet having excellent corrosion resistance and having relative permeability of 20μ r  to 80μ r  wherein a microstructure includes, by volume %, ferrite: 30% to 70% and austenite as a remainder thereof, comprising:
 preparing molten steel comprising, by wt %, carbon (C): 0.1% or less (excepting 0%), silicon (Si): 0.2% to 3.0%, manganese (Mn): 1.0% to 4.0%, chromium (Cr): 19.0% to 23.0%, nickel (Ni): 0.3% to 2.5%, nitrogen (N): 0.18% to 0.3%, copper (Cu): 0.3% to 2.5%, iron (Fe) as a residual component thereof, and other unavoidable impurities; and 
 manufacturing a thin plate by supplying the molten steel to a space between twin rolls of a twin roll strip caster including the twin rolls rotating in opposite directions. 
 
     
     
         7 . The method of manufacturing an induction heatable stainless steel sheet having excellent corrosion resistance of  claim 6 , wherein Md30, where Md30=551−462×(C %+N %)−9.2×Si %−8.1×Mn %−29×(Ni %+Cu %)−13.7×Cr %−18.5×Mo %−68×Al %, of the stainless steel sheet is 80 or less. 
     
     
         8 . The method of manufacturing an induction heatable stainless steel sheet having excellent corrosion resistance of  claim 6 , wherein pitting potential of the stainless steel sheet is 280 mV or more.