Ferritic stainless steel sheet and exhaust member

Abstract

There is provided a ferritic stainless steel sheet including a chemical composition that consists of, in mass %, C: 0.02% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.01 to 0.10%, S: 0.0001 to 0.005%, N: 0.02% or less, Cr: 17.0 to 20.0%, Cu: 1.0 to 1.5%, Ti: 0.05 to 0.3%, Nb: 0.005 to 0.2%, Mo: 0.02 to 0.5%, B: 0.0001 to 0.0030%, Al: 0.005 to 0.5%, Ni: 0.01 to 0.2%, V: 0.01 to 0.2%, optional elements, with the balance: Fe and impurities and satisfies [86 P+33Nb+Mo+4Al≥5.0], in which an area fraction of Cu particles having a diameter of 20 nm or less is 2.0% or less.

1 . A ferritic stainless steel sheet comprising a chemical composition that consists of, in mass %:
 C: 0.02% or less,   Si: 1.0% or less,   Mn: 1.0% or less,   P: 0.01 to 0.10%,   S: 0.0001 to 0.005%,   N: 0.02% or less,   Cr: 17.0 to 20.0%,   Cu: 1.0 to 1.5%,   Ti: 0.05 to 0.3%,   Nb: 0.005 to 0.2%,   Mo: 0.02 to 0.5%,   B: 0.0001 to 0.0030%,   Al: 0.005 to 0.5%,   Ni: 0.01 to 0.2%,   V: 0.01 to 0.2%,   W: 0 to 2.0%,   Sn: 0 to 0.5%,   Mg: 0 to 0.01%,   Sb: 0 to 0.5%,   Zr: 0 to 0.3%,   Ta: 0 to 0.3%,   Hf: 0 to 0.3%,   Co: 0 to 0.3%,   Ca: 0 to 0.01%,   REM: 0 to 0.2%, and   Ga: 0 to 0.3%,   with the balance: Fe and impurities, and   satisfies Formula (i) shown below, wherein   an area fraction of Cu particles having a diameter of 20 nm or less is 2.0% or less:   
       
         
           
             
               
                 
                   
                     
                       
                         86 
                         ⁢ 
                         P 
                       
                       + 
                       
                         33 
                         ⁢ 
                         Nb 
                       
                       + 
                       Mo 
                       + 
                       
                         4 
                         ⁢ 
                         Al 
                       
                     
                     ≥ 
                     5. 
                   
                 
                 
                   
                     ( 
                     i 
                     ) 
                   
                 
               
             
           
         
         where symbols of elements in Formula (i) shown above indicate contents (mass %) of elements contained in the steel sheet, and zero is set to a symbol of an element when the element is not contained. 
       
     
     
         2 . The ferritic stainless steel sheet according to  claim 1 , wherein the chemical composition contains, in mass %, one or more of:
 W: 0.05 to 2.0%,   Sn: 0.01 to 0.5%,   Mg: 0.0002 to 0.01%,   Sb: 0.01 to 0.5%,   Zr: 0.01 to 0.3%,   Ta: 0.01 to 0.3%,   Hf: 0.01 to 0.3%,   Co: 0.01 to 0.3%,   Ca: 0.0001 to 0.01%,   REM: 0.001 to 0.2%, and   Ga: 0.0002 to 0.3%.   
     
     
         3 . The ferritic stainless steel sheet according to  claim 1 , wherein a maximum length of TiN is 15 μm or less. 
     
     
         4 . The ferritic stainless steel sheet according to  claim 2 , wherein a maximum length of TiN is 15 μm or less. 
     
     
         5 . The ferritic stainless steel sheet according to  claim 1 , wherein an amount of precipitating Nb is 0.1% or less in mass %. 
     
     
         6 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 1 . 
     
     
         7 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 5 . 
     
     
         8 . The ferritic stainless steel sheet according to  claim 2 , wherein an amount of precipitating Nb is 0.1% or less in mass %. 
     
     
         9 . The ferritic stainless steel sheet according to  claim 3 , wherein an amount of precipitating Nb is 0.1% or less in mass %. 
     
     
         10 . The ferritic stainless steel sheet according to  claim 4 , wherein an amount of precipitating Nb is 0.1% or less in mass %. 
     
     
         11 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 2 . 
     
     
         12 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 3 . 
     
     
         13 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 4 . 
     
     
         14 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 8 . 
     
     
         15 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 9 . 
     
     
         16 . An exhaust member comprising the ferritic stainless steel sheet according to  claim 10 . 
     
     
         17 . A ferritic stainless steel sheet comprising a chemical composition that comprises, in mass %:
 C: 0.02% or less,   Si: 1.0% or less,   Mn: 1.0% or less,   P: 0.01 to 0.10%,   S: 0.0001 to 0.005%,   N: 0.02% or less,   Cr: 17.0 to 20.0%,   Cu: 1.0 to 1.5%,   Ti: 0.05 to 0.3%,   Nb: 0.005 to 0.2%,   Mo: 0.02 to 0.5%,   B: 0.0001 to 0.0030%,   Al: 0.005 to 0.5%,   Ni: 0.01 to 0.2%,   V: 0.01 to 0.2%,   W: 0 to 2.0%,   Sn: 0 to 0.5%,   Mg: 0 to 0.01%,   Sb: 0 to 0.5%,   Zr: 0 to 0.3%,   Ta: 0 to 0.3%,   Hf: 0 to 0.3%,   Co: 0 to 0.3%,   Ca: 0 to 0.01%,   REM: 0 to 0.2%, and   Ga: 0 to 0.3%,   with the balance comprising: Fe and impurities, and   satisfies Formula (i) shown below, wherein   an area fraction of Cu particles having a diameter of 20 nm or less is 2.0% or less:   
       
         
           
             
               
                 
                   
                     
                       
                         86 
                         ⁢ 
                         P 
                       
                       + 
                       
                         33 
                         ⁢ 
                         Nb 
                       
                       + 
                       Mo 
                       + 
                       
                         4 
                         ⁢ 
                         Al 
                       
                     
                     ≥ 
                     5. 
                   
                 
                 
                   
                     ( 
                     i 
                     ) 
                   
                 
               
             
           
         
         where symbols of elements in Formula (i) shown above indicate contents (mass %) of elements contained in the steel sheet, and zero is set to a symbol of an element when the element is not contained.