| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive Ni-saving type two-phase stainless steel material having corrosion resistance and superior impact toughness. SOLUTION: This stainless steel material includes, by mass%, 0.06% or less C, 0.1-1.5% Si, 0.1-6.0% Mn, 0.05% or less P, 0.005% or less S, 0.25-4.0% Ni, 19.0-23.0% Cr, 0.05-1.0% Mo, 3.0% or less Cu, 0.15-0.25% N, 0.003-0.050% Al and 0.007% or less O, while controlling Ni-bal. represented by expression <1>: Ni-bal.=(Ni+0.5Mn+0.5Cu+30C+30N)-1.1(Cr+1.5Si+Mo+W)+8.2, to -8 to -4, wherein each element name in the expression represents the content (%) and includes 40-70% by an area rate of austenite phases. In the austenite phase, 50 pieces or more of crystal grains, each of which has the major axis of 1-20 μm, exist in the observed visual field of 0.1 mm<SP>2</SP>in a plane parallel to the surface of the steel material. COPYRIGHT: (C)2011,JPO&INPIT |
