US2026009113A1PendingUtilityA1

Ferritic stainless steel

68
Assignee: KK RIKENPriority: Mar 27, 2024Filed: Mar 27, 2024Published: Jan 8, 2026
Est. expiryMar 27, 2044(~17.7 yrs left)· nominal 20-yr term from priority
C22C 38/28C22C 38/06C22C 38/002C22C 38/001C22C 38/26C22C 38/00C22C 38/24C22C 38/22C22C 38/005C22C 38/04C22C 38/02C22C 38/004C22C 38/32
68
PatentIndex Score
0
Cited by
0
References
0
Claims

Abstract

It is an aim of the present disclosure to provide a ferritic stainless steel with excellent oxidation resistance and workability. The ferritic stainless steel of the present disclosure includes a chemical composition containing, in mass %, predetermined amounts of Cr, Al, S, C, N, O, and Nb, with the balance being Fe and inevitable impurities, and content ratios of Al and Cr satisfy expressions (1) and (2): 2Al+Cr≤41 (1), and Al+Cr≥23 (2).

Claims

exact text as granted — not AI-modified
1 - 7 . (canceled) 
     
     
         8 . A ferritic stainless steel comprising:
 a chemical composition containing, in mass %,
 Cr: 14% or more and 27% or less, 
 Al: 7% or more and 13.5% or less, 
 S: 0.0015% or less, 
 C: 0.05% or less, 
 N: 0.2% or less, 
 O: 0.15% or less, and 
 Nb: 0.1% or more and 1.0% or less, 
   with the balance being Fe and inevitable impurities, wherein   content ratios of Al and Cr satisfy expressions (1), (2) and (5):   
       
         
           
             
               
                 
                   
                     
                       
                         2 
                         ⁢ 
                         A 
                         ⁢ 
                           
                         l 
                       
                       + 
                       Cr 
                     
                     ≤ 
                     41 
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     
                       
                         A 
                         ⁢ 
                         l 
                       
                       + 
                       Cr 
                     
                     ≥ 
                     23 
                   
                 
                 
                   
                     ( 
                     2 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     
                       Cr 
                       / 
                       A 
                       ⁢ 
                         
                       l 
                     
                     ≤ 
                     
                       3.2 
                       . 
                     
                   
                 
                 
                   
                     ( 
                     5 
                     ) 
                   
                 
               
             
           
         
       
     
     
         9 . A ferritic stainless steel comprising:
 a chemical composition containing, in mass %,
 Cr: 14% or more and 27% or less, 
 Al: 7% or more and 13.5% or less, 
 S: 0.0015% or less, 
 C: 0.05% or less, 
 N: 0.2% or less, 
 O: 0.15% or less, and 
 Nb: 0.1% or more and 1.0% or less, 
   with the balance being Fe and inevitable impurities, wherein   content ratios of Al and Cr satisfy expressions (1) and (2):   
       
         
           
             
               
                 
                   
                     
                       
                         2 
                         ⁢ 
                         Al 
                       
                       + 
                       Cr 
                     
                     ≤ 
                     41 
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     
                       
                         
                           A 
                           ⁢ 
                           l 
                         
                         + 
                         Cr 
                       
                       ≥ 
                       23 
                     
                     , 
                   
                 
                 
                   
                     ( 
                     2 
                     ) 
                   
                 
               
             
           
         
         the chemical composition further contains at least one of Zr and Hf, content ratios of Zr and Hf satisfy expression (3): 
       
       
         
           
             
               
                 
                   
                     
                       
                         0 
                         .01 
                       
                       ≤ 
                       
                         Zr 
                         + 
                         
                           H 
                           ⁢ 
                           f 
                         
                       
                         
                       ≤ 
                       1. 
                     
                     , 
                   
                 
                 
                   
                     ( 
                     3 
                     ) 
                   
                 
               
             
           
         
       
       and
 a shape of the ferritic stainless steel is wire shape or strip shape. 
 
     
     
         10 . The ferritic stainless steel according to  claim 8 , wherein
 the chemical composition further contains, in mass %,
 Ti: 0.05% or more and 1.0% or less, and 
   Al+Cr is 26 or more.   
     
     
         11 . The ferritic stainless steel according to  claim 9 , wherein
 the chemical composition further contains, in mass %,
 Ti: 0.05% or more and 1.0% or less, and 
   Al+Cr is 26 or more.   
     
     
         12 . The ferritic stainless steel according to  claim 9 , wherein
 content ratios of Al and Cr satisfy expression (5):   
       
         
           
             
               
                 
                   
                     
                       Cr 
                       / 
                       Al 
                     
                     ≤ 
                     
                       3.2 
                       . 
                     
                   
                 
                 
                   
                     ( 
                     5 
                     ) 
                   
                 
               
             
           
         
       
     
     
         13 . The ferritic stainless steel according to  claim 8 , wherein a reduction of area in a tensile test at room temperature is 40% or more. 
     
     
         14 . The ferritic stainless steel according to  claim 10 ,
 the chemical composition further contains, in mass %,
 REM: 0.01% or less, and 
   content ratios of Al, Cr, S, and REM satisfy expression (4):   
       
         
           
             
               
                 
                   
                     
                       - 
                       1. 
                     
                     ≤ 
                     
                       
                         ( 
                         
                           S 
                           - 
                           
                             REM 
                             / 
                             5 
                           
                         
                         ) 
                       
                       × 
                       
                         
                           ( 
                           
                             
                               2 
                               ⁢ 
                               Al 
                             
                             + 
                             Cr 
                           
                           ) 
                         
                         2 
                       
                     
                     ≤ 
                     
                       1.3 
                       . 
                     
                   
                 
                 
                   
                     ( 
                     4 
                     ) 
                   
                 
               
             
           
         
       
     
     
         15 . A ferritic stainless steel comprising:
 a chemical composition containing, in mass %,
 Cr: 14% or more and 27% or less, 
 Al: 7% or more and 13.5% or less, 
 S: 0.0015% or less, 
 C: 0.05% or less, 
 N: 0.2% or less, 
 O: 0.15% or less, 
 Nb: 0.1% or more and 1.0% or less, and 
 Ti: 0.05% or more and 1.0% or less, 
   with the balance being Fe and inevitable impurities, wherein content ratios of Al and Cr satisfy expressions (1) and (2):   
       
         
           
             
               
                 
                   
                     
                       
                         2 
                         ⁢ 
                         Al 
                       
                       + 
                       Cr 
                     
                     ≤ 
                     41 
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     
                       
                         
                           A 
                           ⁢ 
                           l 
                         
                         + 
                         Cr 
                       
                       ≥ 
                       26 
                     
                     , 
                   
                 
                 
                   
                     ( 
                     2 
                     ) 
                   
                 
               
             
           
         
         the chemical composition further contains at least one of Zr and Hf, content ratios of Zr and Hf satisfy expression (3): 
       
       
         
           
             
               
                 
                   
                     
                       
                         0 
                         .01 
                       
                       ≤ 
                       
                         Zr 
                         + 
                         Hf 
                       
                       ≤ 
                       1. 
                     
                     , 
                   
                 
                 
                   
                     ( 
                     3 
                     ) 
                   
                 
               
             
           
         
         the chemical composition further contains, in mass %,
 REM: 0.01% or less, 
 
         content ratios of Al, Cr, S, and REM satisfy expression (4): 
       
       
         
           
             
               
                 
                   
                     
                       
                         - 
                         1. 
                       
                       ≤ 
                       
                         
                           ( 
                           
                             S 
                             - 
                             
                               REM 
                               / 
                               5 
                             
                           
                           ) 
                         
                         × 
                         
                           
                             ( 
                             
                               
                                 2 
                                 ⁢ 
                                 Al 
                               
                               + 
                               Cr 
                             
                             ) 
                           
                           2 
                         
                       
                       ≤ 
                       1.3 
                     
                     , 
                   
                 
                 
                   
                     ( 
                     4 
                     ) 
                   
                 
               
             
           
         
       
       and
 a shape of the ferritic stainless steel is wire shape, strip shape, tube shape or plate shape.

Cited by (0)

No later patents cite this yet.

References (0)

No backward citations on record.