Duplex stainless steel and cast article thereof
AssigneeYamaha Marine Kabushiki Kaisha
InventorTakanobu Suzuki
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Abstract
A generally Mo-free, ferrite-austenite duplex stainless steel has a ferrite phase area ratio of about 20 to about 60% and a composition containing, in mass %, not more than about 0.08% of C, about 0.5 to about 1.5% of Si, not more than about 1.0% of Mn, about 4.0 to about 8.0% of Ni, about 23 to about 27% of Cr, about 2.0 to about 6.0% of Cu, about 0.05 to about 0.3% of N, and the balance being Fe and generally unavoidable impurities.
Claims12
A duplex stainless steel characterized by comprising Fe as a major component and further containing C, Si, Mn, Ni, Cr, Cu, Ni and generally unavoidable impurities, and comprising a ferrite phase and an austenite phase with an area ratio of the ferrite phase being not less than about 20% but not more than about 60%.
A duplex stainless steel characterized by comprising, in mass %:
- up to about 0.08% of C,
- not less than about 0.5% but not more than about 1.5% of Si,
- up to about 1.0% of Mn,
- not less than about 4.0% but not more than about 8.0% of Ni,
- not less than about 23% but not more than about 27% of Cr,
- not less than about 2.0% but not more than about 6.0% of Cu,
- not less than about 0.05% but not more than about 0.3% of N, and
- the balance being Fe and generally unavoidable impurities, and
- characterized by comprising a ferrite phase and an austenite phase with an area ratio of the ferrite phase being not less than about 20% but not more than about 60%.
Dependencies are inferred from the claim text.