Fatigue-creep interaction and fracture model of Cr-mo-V heat resistant steel in steam pipe line

The fracture map was constructed on the basis of the combination of macro-mechanical properties and micro-fracture model. The mechanical behaviour under fatigue-creep interaction (FC) of (2CrlMoV steel, all the information including fracture life, strain rate, and main factors controlling fracture model (FF,FCF,CFF,FCC,CFC and CC) may be described on the map. The 12CrlMoV steel has weak resistance at 588°C, which is in the ratio of 1 to fatigue resistance. An FC region occurs widely on the map of steel, saying, the FCC (fatigue crack nucleation, creep propagation and fracture) fracture model may be relatively easily appeared. After the steel was in the service for steam pipe at 540°C for 2×10⁵h, the FC properties are remarkably reduced and the fracture model changes too.