Patent Number: 6,332,934

Title: Martensitic stainless steel for seamless steel pipe

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%.

Inventors: Tanida; Mutsumi (Wakayama, JP), Nakanishi; Tetsuya (Wakayama, JP)

Assignee: Sumitomo Metal Industries, Ltd.

International Classification: C22C 38/40 (20060101); C22C 38/04 (20060101); C22C 38/00 (20060101); C22C 38/18 (20060101); C21D 8/10 (20060101); C22C 038/18 (); C22C 038/60 (); C22C 038/32 ()

Expiration Date: 12/25/2018