Abstract:
Samples of duplex stainless steel, consisting of iron-based Cr-Ni-Mo alloy containing some other elements undergoing various heat treatments after having been wrought at 1150°C, have been investigated using X-ray diffraction, thermal analysis and metallographic techniques. It is determined that some intermetallic phases such as Laves, σ G, μ, R, χ, and some carbide phases as such M23C6, M7C3, M6C may be found in these samples and that the ratio of carbide phases decreased in samples annealed at 950°C. In samples cooled in liquid nitrogen, it is seen that some dissolving elements in the matrix have accumulated around the σ phases and some precipitation phases have occurred. It is concluded that the use of annealing of this material at 950°C affects the chemical, mechanical and other properties adversely. © 1997 Elsevier Science S.A.