Effect of alloying on the nucleation and growth of laves phase in the 9-10% CR-3% CO martensitic steels during creep

Abstract

Five Co-modified P92-type steels with different contents of Cr,W, Mo, B, N, and Re have been examined to evaluate the effect of the chemical composition on the evolution of Laves phase during creep at 650 C. The creep tests have been carried out at 650 C under various applied initial stresses ranging from 80 to 200 MPa until rupture. An increase in the B and Cr contents leads to a decrease in the size and volume fraction of M₂₃C₆ carbides precipitated during tempering and an increase in their number particle density along the boundaries. In turns, this affects the amount of the nucleation sites for Laves phase during creep