Study on High-temperature Creep Rupture Test and Microstructure Evolution of P92 Steel Pipe

The high temperature stress rupture test is conducted at different temperatures to the P92 steel pipe,and based on the data form the test,the 625℃/10⁵ h stress rupture strength is extrapolated to 103.8 MPa,which means that the pipe has excellent high-temperature stress rupture property. Furthermore the metallographic microstructure of the P92 steel pipe at high temperature and the evolution thereof at high temperature are analyzed. And it is revealed via the analysis that due to being long time held under a high temperature condition,the high-temperature stress ruptures test specimen of the P92 pipe has such microstructure changes as coarsening of martensite lath and coarsening of precipitation phases of M₂₃C₆ and MX;and meanwhile,the time-caused intermetallic compound(IMC),the Laves phase is developed in the high temperature stress state,and thus the creep rupture strength of the material is reduced.