Precipitation in superaustenitic stainless steels with partial replacement of Mo by W

摘要

Precipitation of secondary phases at 900 deg C has been studied in superaustenitic stainless steels with Mo aprtly replaced by W.In the base Mo-alloyed material,the main precipiates after short time ageing were #sigma#.#chi# and Laves related related phases,with the latter vanishing after long ageing times.Partial replacement of Mo with W suppresses #sigma# but promotes formation of Laves type phases,generally giving a lower structural stability.All precipitated phases have been identified by electron diffraction and specifically the formation of C14 Laves and #um# phases and associated faults have been studied.