| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide ferritic stainless steel for an exhaust heat recovery unit having corrosion resistance to exhaust gas condensed water. <P>SOLUTION: The ferritic stainless steel contains, by mass, 0.03% or less of C, 0.05% or less of N, more than 0.1% and 1% or less of Si, 0.02% or more and 1.2% or less of Mn, 17% or more and 23% or less of Cr, 0.002% or more and 0.5% or less of Al, two or three of Ni, Cu and Mo, in which 0.25% or more and 1.5% or less of Ni, 0.25% or more and 1% or less of Cu, and 0.5% or more and 2% or less of Mo, and one or both of Nb and Ti, and satisfies formulas (1): 8(C+N)+0.03≤Nb+Ti≤0.6 and (2): Si+Cr+Al+[Nb+Ti-8(C+N)]≥17.5. The ferritic stainless steel has a remaining portion consisting of Fe and inevitable impurities, and is formed on the surface with an oxide film containing 40% or more of Cr, Nb, Si and Al in total of cation fraction. <P>COPYRIGHT: (C)2013,JPO&INPIT |
