Work-hardened material from stainless steel

Abstract

A stainless steel sheet has a chemical composition consisting of 0.15 mass % or less of C, 1.0 mass % or less of Si, 1.0 mass % or less of Mn, 0.005 mass % or less of S, 10-20 mass % of Cr, 0.5 mass % or less of Ni, 0.001-0.05 mass % of Al, optionally one or more of 0.5-2.0 mass % of Mo, 0.5-3.0 mass % of Cu and 0.05-1.0 mass % of Nb, and the balance being Fe except inevitable impurities. It is strengthened by a work-hardened ferritic structure, wherein Al 2 O 3 and/or Al 2 O 3 .MgO inclusions of 10 μm or less in size are distributed with cleanliness of 0.06% or less. It is useful as lightweight material for parts and structural members of home electric appliances, office automation devices and so on, due to excellent bendability in addition to high yield strength of 700 N/mm 2 or more.

1 - 3 . (canceled)  
   
   
       4 . A work-hardened stainless steel sheet comprising: 
 a chemical composition consisting of 0.15 mass % or less of C, 1.0 mass % or less of Si, 1.0 mass % or less of Mn, 0.005 mass % or less of S, 10-20 mass % of Cr, 0.5 mass % or less of Ni, 0.001-0.05 mass % of Al and the balance being Fe except inevitable impurities; and    a work-hardened ferritic structure, wherein at least one of Al 2 O 3  and Al 2 O 3 .MgO inclusions of 10 μm or less in size are distributed with an index of cleanliness of 0.06% or less.    
   
   
       5 . The work-hardened stainless steel sheet of  claim 4 , wherein the stainless steel sheet has yield strength within a range of 500-900 N/mm 2 .  
   
   
       6 . A work-hardened stainless steel sheet comprising: 
 a chemical composition consisting of 0.15 mass % or less of C, 1.0 mass % or less of Si, 1.0 mass % or less of Mn, 0.005 mass % or less of S, 10-20 mass % of Cr, 0.5 mass % or less of Ni, 0.001-0.05 mass % of Al, and at least one of 0.5-2.0 mass % of Mo, 0.5-3.0 mass % of Cu and 0.05-1.0 mass % of Nb, and the balance being Fe except inevitable impurities; and    a work-hardened ferritic structure, wherein at least one of Al 2 O 3  and Al 2 O 3 .MgO inclusions of 10 μm or less in size are distributed with an index of cleanliness of 0.06% or less.    
   
   
       7 . The work-hardened stainless steel sheet of  claim 6 , wherein the stainless steel sheet has yield strength within a range of 500-900 N/mm 2 .