Ferritic stainless steel

Abstract

Provided is a ferritic stainless steel sheet. The steel sheet has a chemical composition containing, by mass %, C: 0.010% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.040% or less, S: 0.030% or less, Cr: 17.0% or more and 18.5% or less, N: 0.015% or less, Nb: 0.40% or more and 0.80% or less, Ti: 0.10% or more and 0.40% or less, Al: 0.20% or less, Ni: 0.05% or more and 0.40% or less, Co: 0.01% or more and 0.30% or less, Mo: 0.02% or more and 0.30% or less, Cu: 0.02% or more and 0.40% or less, and the balance being Fe and inevitable impurities, in which expression (1) below is satisfied. C %+N %: 0.018% or less  (1) In expression (1), C % and N % respectively denote the contents (mass %) of C and N.

1 . Ferritic stainless steel having a chemical composition containing, by mass %,
 C: 0.010% or less,   Si: 1.0% or less,   Mn: 1.0% or less,   P: 0.040% or less,   S: 0.030% or less,   Cr: 17.0% or more and 18.5% or less,   N: 0.015% or less,   Nb: 0.40% or more and 0.80% or less,   Ti: 0.10% or more and 0.40% or less,   Al: 0.20% or less,   Ni: 0.05% or more and 0.40% or less,   Co: 0.01% or more and 0.30% or less,   Mo: 0.02% or more and 0.30% or less,   Cu: 0.02% or more and 0.40% or less, and   the balance being Fe and inevitable impurities,   wherein expression (1) below is satisfied:
   C %+N %: 0.018% or less  (1),
 
   where, in expression (1), C % and N % respectively denote the contents (mass %) of C and N.   
     
     
         2 . The ferritic stainless steel according to  claim 1 , wherein the chemical composition further contains, by mass %, one, two, or all selected from
 Ca: 0.0005% or more and 0.0030% or less,   Mg: 0.0002% or more and 0.0020% or less, and   B: 0.0002% or more and 0.0020% or less.   
     
     
         3 . The ferritic stainless steel according to  claim 1 , wherein the chemical composition further contains, by mass %, one, two, or all selected from
 V: 0.01% or more and 0.50% or less,   W: 0.02% or more and 0.30% or less, and   Zr: 0.005% or more and 0.50% or less.   
     
     
         4 . The ferritic stainless steel according to  claim 2 , wherein the chemical composition further contains, by mass %, one, two, or all selected from
 V: 0.01% or more and 0.50% or less,   W: 0.02% or more and 0.30% or less, and   Zr: 0.005% or more and 0.50% or less.