Computer simulation of the high temperature creep behaviour of Cr–Mo steels

Continuum damage mechanics (CDM) based model developed by Dyson and McLean has been used to simulate creep behaviour of 2.25Cr–1Mo steel having a large creep database. Material parameters evaluated for this steel were used as the initial set to estimate material parameters for 9CrMoVNb steel where only a limited creep database was available. A simple iteration scheme and optimisation procedure has been developed. The simulated plots were found to describe experimental data fairly well. Using an additional data on elastic modulus stress relaxation test was also simulated. The nature of such plots was quite similar to that of the experimental plots.

► CDM based models have been employed to describe the creep behaviour of Cr–Mo steel.
► The material parameters for 2.25Cr1Mo and 9CrMoVNb steel have been computed.
► Model predictions are consistent with experimental data for the computed parameters.
► 9CrMoVNb steel has superior creep resistance compared to 2.25Cr–1Mo steel.
► CDM model supports a correlation between creep and stress relaxation behaviour of steel.