Method of Manufacturing Thin Martensitic Stainless Steel Sheet Using Strip Caster with Twin Rolls and Thin Martensitic Stainless Steel Sheet Manufactured by the Same

Abstract

Provided is a method of manufacturing a THIN MARTENSITIC STAINLESS STEEL SHEET by casting a thin cast strip using a strip caster including a pair of rotating strip casting rolls and hot rolling the thin cast strip, wherein any one of conditions (a) and (b) is satisfied during the hot rolling, and a THIN MARTENSITIC STAINLESS STEEL SHEET manufactured by the same: (a) Bending force of rolling rolls: 30 to 500 kN (b) Size of crowns of rolling rolls: 50 to 250 μm.

What is claimed is: 
     
         1 . A method of manufacturing a THIN MARTENSITIC STAINLESS STEEL SHEET by casting a thin cast strip using a strip caster comprising a pair of rotating strip casting rolls and hot rolling the thin cast strip, wherein any one of conditions (a) and (b) is satisfied during the hot rolling:
 (a) Bending force of rolling rolls: 30 to 500 kN   (b) Size of crowns of rolling rolls: 50 to 250%.   
     
     
         2 . The method of  claim 1 , wherein the bending force of the rolling rolls is 30 to 300 kN. 
     
     
         3 . The method of  claim 1 , wherein the size of the crowns of the rolling rolls is 50 to 200 μm. 
     
     
         4 . The method of  claim 1 , wherein the stainless thin steel sheet comprises 0.3 wt % to 0.8 wt % of C, 12.0 wt % to 16.0 wt % of Cr, 0.2 wt % to 1.0 wt % of Si, 0.2 wt % to 1.0 wt % of Mn, 0.2 wt % to 1.0 wt % of Ni, 0.01 wt % to 0.1 wt % of N, 0.03 wt % or less of P, and 0.03 wt % or less of S, and also includes Fe and other inevitable impurities. 
     
     
         5 . The method of  claim 1 , wherein a difference between reduction ratios of the central part and the edge of the thin cast strip is 0.8% or less during hot rolling. 
     
     
         6 . A THIN MARTENSITIC STAINLESS STEEL SHEET, comprising 0.3 wt % to 0.8 wt % of C, 12.0 wt % to 16.0 wt % of Cr, 0.2 wt % to 1.0 wt % of Si, 0.2 wt % to 1.0 wt % of Mn, 0.2 wt % to 1.0 wt % of Ni, 0.01 wt % to 0.1 wt % of N, 0.03 wt % or less of P, and 0.03 wt % or less of S, and also includes Fe and other inevitable impurities, wherein a size of an edge crack is no more than 30 mm.