Ferritic stainless steel

Abstract

A ferritic stainless steel having a good thermal fatigue property and oxidation resistance while minimizing the contents of Mo, W, and Nb which are expensive elements and minimizing the content of Cu which deteriorates oxidation resistance and workability.

1 . A ferritic stainless steel comprising:
 C: 0.020% or less, by mass %;   Si: 3.0% or less, by mass %;   Mn: 1.0% or less, by mass %;   P: 0.040% or less, by mass %,   S: 0.030% or less, by mass %;   Cr: 10.0% to 16.0%, by mass %;   N: 0.020% or less, by mass %;   Al: 1.4 to 4.0%, by mass %;   Ti: more than 0.15% and 0.5% or less, by mass %;   Ni: 0.05 to 0.5%, by mass %; and   Fe and unavoidable impurities, the ferritic stainless steel satisfying the following formula (1):
   Al %/Cr %≧0.14  (1)
 
   
       where Al % and Cr % in the formula (1) respectively denote an Al content and a Cr content by mass %. 
     
     
         2 . The ferritic stainless steel according to  claim 1 , further comprising at least one Nb: 0.01 to 0.15%, by mass %, and Cu: 0.01% to 0.4%, by mass %. 
     
     
         3 . The ferritic stainless steel according to  claim 1 , further comprising at least one of Mo: 0.02 to 0.5%, by mass %, and W: 0.02 to 0.3%, by mass %. 
     
     
         4 . The ferritic stainless steel according to  claim 1 , further comprising at least one of REM: 0.001 to 0.10%, by mass %, Zr: 0.01 to 0.5%, by mass %, V: 0.01 to 0.5%, by mass %, and Co: 0.01 to 0.5%, by mass %. 
     
     
         5 . The ferritic stainless steel according to  claim 1 , further comprising at least one of B: 0.0002 to 0.0050%, by mass %, Mg: 0.0002 to 0.0020%, by mass %, and Ca: 0.0005 to 0.0030%, by mass %. 
     
     
         6 . The ferritic stainless steel according to  claim 2 , further comprising at least one of Mo: 0.02 to 0.5%, by mass %, and W: 0.02 to 0.3%, by mass %. 
     
     
         7 . The ferritic stainless steel according to  claim 2 , further comprising at least one of REM: 0.001 to 0.10%, by mass %, Zr: 0.01 to 0.5%, by mass %, V: 0.01 to 0.5%, by mass %, and Co: 0.01 to 0.5%, by mass %. 
     
     
         8 . The ferritic stainless steel according to  claim 3 , further comprising at least one of REM: 0.001 to 0.10%, by mass %, Zr: 0.01 to 0.5%, by mass %, V: 0.01 to 0.5%, by mass %, and Co: 0.01 to 0.5%, by mass %. 
     
     
         9 . The ferritic stainless steel according to  claim 2 , further comprising at least one of B: 0.0002 to 0.0050%, by mass %, Mg: 0.0002 to 0.0020%, by mass %, and Ca: 0.0005 to 0.0030%, by mass %. 
     
     
         10 . The ferritic stainless steel according to  claim 3 , further comprising at least one of B: 0.0002 to 0.0050%, by mass %, Mg: 0.0002 to 0.0020%, by mass %, and Ca: 0.0005 to 0.0030%, by mass %. 
     
     
         11 . The ferritic stainless steel according to  claim 4 , further comprising at least one of B: 0.0002 to 0.0050%, by mass %, Mg: 0.0002 to 0.0020%, by mass %, and Ca: 0.0005 to 0.0030%, by mass %.