Martensitic stainless steel for seamless steel pipe
AssigneeSumitomo Metal Industries, Ltd.
InventorsMutsumi Tanida, Tetsuya Nakanishi
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Abstract
A martensitic stainless steel for seamless steel pipes, excellent in descaling property and machinability, having the following chemical composition, by weight %; 0.025 to 0.22% of C, 10.5 to 14% of Cr, 0.16 to 1.0% of Si, 0.05 to 1.0% of Mn, 0.05% or less of Al, 0.100% or less of N, 0.25% or less of V, 0.020% or less of P, 0.004 to 0.015% of S, and the balance Fe and impurities, This steel may include 0.0002 to 0.0050% of B, and/or 0.0005 to 0.005% of Ca. In this case, the upper limit of S may be extended up to 0.018%. Preferably, Al is limited to less than 0.01%.
Claims20
A seamless steel pipe made of a martensitic stainless steel characterized by consisting of, by weight %, 0.025 to 0.22% of C, 10.5 to 14% of Cr, 0.16 to 1.0% of Si, 0.05 to 1.0% of Mn, 0.05% or less of Al, 0.0005 to 0.0011% of Ca, 0.100% or less of N, 0.25% or less of V, 0.020% or less of P, 0.004 to 0.018% of S, and the balance Fe anad impurities, and having a micro-structure of about 95% or more martensite by area.
A seamless steel pipe made of a martensitic stainless steel characterized by consisting of, by weight %, 0.025 to 0.22% of C, 10.5 to 14% of Cr, 0.16 to 1.0% of Si, 0.05 to 1.0% of Mn, 0.0002 to 0.0050% of B, 0.05% or less of Al, 0.0005 to 0.0011% of Ca, 0.100% or less of N, 0.25% or less of V, 0.020% or less of P, 0.004 to 0.018% of S, and the balance Fe and impurities and having a micro-structure of about 95% or more martensite by area.
Dependencies are inferred from the claim text.