Heat-resistant ferritic stainless steel sheet having excellent oxidation resistance

Abstract

A heat-resistant ferritic stainless steel sheet having excellent oxidation resistance while being low in cost and optimal for use in exhaust system components, wherein mass % falls within the following ranges: C: 0.015% or less, N: 0.020% or less, P: 0.04% or less, S: 0.001% or less, Si: 0.3-1.5% or less, Mn: 0.3-0.7% or less, Cr: 11.0-17.0%, Cu: 0.8-1.5%, Ni: 0.05-1.0%, V: 0.5% or less, Al: over 0.01 up to 0.1%, Ti: 10(C+N) to 0.3%. Also, the element content of the elements in the ferritic stainless steel sheet having excellent oxidation and thermal resistance has been mutually adjusted in a manner such that the value of γ defined in formula (1) is 35 or less. γ=23[% Ni]+9[% Cu]+7[% Mn]−11.5[% Cr]−11.5[% Si]−52[% Al]−49[[Ti %]−4([% C]+[% N])]−23[% V]−12[% Mo]−47[% Nb]+189  (1)

1 . A ferritic stainless steel sheet having excellent heat resistant and oxidation resistance comprising: by mass %,
 C: 0.015% or less,   N: 0.020% or less,   P: 0.04% or less,   S: 0.01% or less,   Si: 0.3 to 1.5%,   Mn: 0.3 to 0.7%,   Cr: 11.0 to 17.0%,   Cu: 0.8 to 1.5%,   Ni: 0.05 to 1.0%,   V: 0.5% or less,   Al: 0.01 to 0.1%, and   Ti: 10(C+N) to 0.3%;   the amounts of the elements being mutually adjusted such that the γ-value which is defined by the following formula (1), becomes 35 or less, and   has a balance of Fe and unavoidable impurities:
   γ=23[% Ni]+9[% Cu]+7[% Mn]−11.5[% Cr]−11.5[% Si]−52[% Al]−49[[Ti %]−4([% C]+[% N])]−23 [% V]−12[% Mo]−47[% Nb]+189  (1).
 
   
     
     
         2 . The ferritic stainless steel sheet having excellent heat-resistance and oxidation resistance as set forth in  claim 1 , wherein said stainless steel sheet further comprises, by mass %, at least one or more selected from the group consisting of
 Nb: 0.001 to 0.3%,   Mo: 0.01 to 0.5%, and   B: 0.0003 to 0.0050%.   
     
     
         3 . The ferritic stainless steel sheet having excellent heat-resistance and oxidation resistance as set forth in  claim 1 , wherein said stainless steel sheet further comprises, by mass %, at least one or more selected from the group consisting of
 Zr: 1.0% or less,   Sn: 1.0% or less, and   Co: 0.5% or less.   
     
     
         4 . The ferritic stainless steel sheet having excellent heat-resistance and oxidation resistance as set forth in  claim 2 , wherein said stainless steel sheet further comprises, by mass %, at least one or more selected from the group consisting of
 Zr: 1.0% or less,   Sn: 1.0% or less, and   Co: 0.5% or less.