Quantitative investigation of microstructural evolution of two melts of the martensitic rotor steel X12CrMoWVNbN10-1-1 during long term creep

摘要

The group of 9- to 12%CrMo(W)VNb(N,B)-steels underwent intensive developments under various Japanese, American and European research programmes. The goal of research is to develop turbine rotor steels with high creep strength and user-friendly general behaviour. One result of the European research programme COST 501 is the rotor steel of type X12CrMoWVNbNlO-1-1. Two melts of this material exhibited different creep strengths. The lifetime until rupture was considerably longer for both melts. The aim of the present work is to explain this difference in terms of microstructural differences.