Superior creep resistance of a high-Cr steel with Re additives

Abstract

Re-containing 10Cr-3Co-3W martensitic steel with low nitrogen and high boron contents exhibited a rupture time of 10,987 h at 650 C/140 MPa. This superior creep resistance was caused by partially saved tempered martensite lath structure due to precipitation of M₂₃C₆ carbides and Laves phase chains on lath boundaries as well as their high resistance to coarsening.M₂₃C₆ carbides were characterized by decreased interfacial energy that resulted in the retention of the orientation relationship between M₂₃C₆ carbides and ferritic matrix. Re slowed down diffusion of W, Mo and Cr atoms