High-strength steel sheet for can and method for manufacturing same

Abstract

A steel sheet for a can has a yield strength of 450 MPa or more, and the occurrence of cracking at a slab corner being prevented in a continuous casting process. The steel sheet contains 0.03%-0.10% C, 0.01%-0.5% Si, 0.001%-0.100% P, 0.001%-0.020% S, 0.01%-0.10% Al, 0.005%-0.012% N, and the balance being Fe and incidental impurities, in which when Mnf=Mn [% by mass]−1.71×S [% by mass], Mnf is in the range of 0.3 to 0.6. The steel sheet has microstructures that do not contain a pearlite microstructure.

1 . A high-strength steel sheet for a can comprising, on a mass percent basis, 0.03%-0.10% C, 0.01%-0.5% Si, 0.001%-0.100% P, 0.001%-0.020% S, 0.01%-0.10% Al, 0.005%-0.012% N, the balance being Fe and incidental impurities, and microstructures that do not contain a pearlite microstructure, wherein when Mnf=Mn[% by mass]−1.71×S[% by mass], Mnf is in the range of 0.3 to 0.6. 
     
     
         2 . The high-strength steel sheet according to  claim 1 , wherein, on a mass percent basis, S content is in the range of 0.001% to 0.005%, and/or Al content is in the range of 0.01% to 0.04%. 
     
     
         3 . The high-strength steel sheet according to  claim 1 , wherein yield strength is in a range of 450 to 470 MPa after a lacquer baking treatment performed at 210° C. for 20 minutes. 
     
     
         4 . The high-strength steel sheet according to  claim 2 , wherein yield strength is in a range of 450 to 470 MPa after lacquer baking treatment at 210° C. for 20 minutes. 
     
     
         5 . A method for manufacturing a high-strength steel sheet according to  claim 1 , comprising:
 a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is set to 800° C. or lower, or 900° C. or higher, and   annealing the slab after cold rolling, at an annealing temperature set to less than the A 1  transformation point.   
     
     
         6 . A method for manufacturing a high-strength steel sheet according to  claim 2 , comprising:
 a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is set to 800° C. or lower, or 900° C. or higher, and   annealing the slab after cold rolling, at an annealing temperature set to less than the A 1  transformation point.   
     
     
         7 . A method for manufacturing a high-strength steel sheet according to  claim 3 , comprising:
 a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is set to 800° C. or lower, or 900° C. or higher, and   annealing the slab after cold rolling, at an annealing temperature set to less than the A 1  transformation point.   
     
     
         8 . A method for manufacturing a high-strength steel sheet according to  claim 4 , comprising:
 a slab by vertical-bending type continuous casting or bow type continuous casting, wherein surface temperature of a slab corner in a region where the slab undergoes bending deformation or unbending deformation is set to 800° C. or lower, or 900° C. or higher, and   annealing the slab after cold rolling, at an annealing temperature set to less than the A 1  transformation point.