Creep behavior and microstructural evolution of a 9%Cr steel with high B and low N contents

The creep behavior of a 3%Co modified P92-type steel with high content of boron and low content of nitrogen was studied. The precipitation of Laves phase at lath boundaries provides a rapid decrease in the strain rate during transient creep. The finely dispersed (V,Nb)(C,N) carbonitrides uniformly distributed throughout and M23C6 carbides located at various boundaries/subboundaries result in extended steady-state creep. Gradual coarsening and an...