| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a duplex stainless steel superior in toughness which is used for sea water-resistant members, in particular, such as shafts, a valve, a flange, piping and a measuring unit. <P>SOLUTION: The duplex stainless steel has a composition containing by mass%, ≤0.030% C, ≤1.00% Si, ≤1.20% Mn, 22-27% Cr, 4.0-8.0% Ni, 1.0-5.0% Mo, 0.1-0.3% N, >0.0010 and ≤0.0200% S, >0.0005 and ≤0.0100% Ca and the balance Fe with inevitable impurities. The duplex stainless steel has a ferrite content of 40-80 vol% and has a γ-phase with ≥10 μm major axis in an amount of ≥80 pieces per 1 mm<SP POS="POST">2</SP>in an optical microscopic structure observation. <P>COPYRIGHT: (C)2012,JPO&INPIT |
