Hot-rolled and annealed ferritic stainless steel sheet and method for producing the same

Abstract

To provide a hot-rolled and annealed ferritic stainless steel sheet having sufficient corrosion resistance and excellent punching workability, a predetermined dimensional accuracy being obtained without cracking when the steel sheet is formed into a thick-walled flange by punching work, and a method for producing the hot-rolled and annealed ferritic stainless steel sheet.The hot-rolled and annealed ferritic stainless steel sheet has a chemical composition containing, on a mass percent basis, C: 0.001% to 0.020%, Si: 0.05% to 1.00%, Mn: 0.05% to 1.00%, P: 0.04% or less, S: 0.01% or less, Al: 0.01% to 0.10%, Cr: 10.0% to 20.0%, Ni: 0.50% to 2.00%, Ti: 0.10% to 0.40%, and N: 0.001% to 0.020%, the balance being Fe and incidental impurities; and has a metal microstructure which is a single ferrite phase microstructure having an average grain size of 5 to 20 μm.

1 . A hot-rolled and annealed ferritic stainless steel sheet having a chemical composition containing, on a mass percent basis:
 C: 0.001% to 0.020%,   Si: 0.05% to 1.00%,   Mn: 0.05% to 1.00%,   P: 0.04% or less,   S: 0.01% or less,   Al: 0.01% to 0.10%,   Cr: 10.0% to 20.0%,   Ni: 0.50% to 2.00%,   Ti: 0.10% to 0.40%, and   N: 0.001% to 0.020%, the balance being Fe and incidental impurities; and   having a metal microstructure which is a single ferrite phase microstructure having an average grain size of 5 to 20 μμm.   
     
     
         2 . The hot-rolled and annealed ferritic stainless steel sheet according to  claim 1 , further containing, on a mass percent basis, one or two or more selected from:
 Cu: 0.01% to 1.00%,   Mo: 0.01% to 2.00%,   W: 0.01% to 0.20%, and   Co: 0.01% to 0.20%.   
     
     
         3 . The hot-rolled and annealed ferritic stainless steel sheet according to  claim 1 , further containing, on a mass percent basis, one or two or more selected from:
 V: 0.01% to 0.20%,   Nb: 0.01% to 0.10%,   Zr: 0.01% to 0.20%,   REM: 0.001% to 0.100%,   B: 0.0002% to 0.0025%,   Mg: 0.0005% to 0.0030%, and   Ca: 0.0003% to 0.0030%.   
     
     
         4 . A method for producing the hot-rolled and annealed ferritic stainless steel sheet according to  claim 1 , comprising:
 performing hot-rolled steel sheet annealing in which a hot-rolled steel sheet produced through a hot-rolling step is held at 600° C. or higher and lower than 750° C. for 1 minute to 24 hours.   
     
     
         5 . The hot-rolled and annealed ferritic stainless steel sheet according to  claim 2 , further containing, on a mass percent basis, one or two or more selected from:
 V: 0.01% to 0.20%,   Nb: 0.01% to 0.10%,   Zr: 0.01% to 0.20%,   REM: 0.001% to 0.100%,   B: 0.0002% to 0.0025%,   Mg: 0.0005% to 0.0030%, and   Ca: 0.0003% to 0.0030%.   
     
     
         6 . A method for producing the hot-rolled and annealed ferritic stainless steel sheet according to  claim 2 , comprising:
 performing hot-rolled steel sheet annealing in which a hot-rolled steel sheet produced through a hot-rolling step is held at 600° C. or higher and lower than 750° C. for 1 minute to 24 hours.   
     
     
         7 . A method for producing the hot-rolled and annealed ferritic stainless steel sheet according to  claim 3 , comprising:
 performing hot-rolled steel sheet annealing in which a hot-rolled steel sheet produced through a hot-rolling step is held at 600° C. or higher and lower than 750° C. for 1 minute to 24 hours.   
     
     
         8 . A method for producing the hot-rolled and annealed ferritic stainless steel sheet according to  claim 5 , comprising:
 performing hot-rolled steel sheet annealing in which a hot-rolled steel sheet produced through a hot-rolling step is held at 600° C. or higher and lower than 750° C. for 1 minute to 24 hours.