Experimental characterization and modelling of the creep properties of a P92 weldment

In order to study the rupture phenomena of welded structures made of P92 steel, a weldment was obtained in a P92 seamless pipe portion. Cylindrical smooth and notched cross-weld specimens (CWS) were cut from the weld and submitted to tensile and creep uniaxial tests at 575°C. The results of these tests are presented and discussed. A continuum model is proposed in order to simulate the deformation and damage mechanisms of the base metal, heat affected zone and weld metal within welded structures. The material parameters for the model at 575°C were obtained for the different microstructural regions on the basis of literature data and on the current results on smooth CWS creep tests. It is then shown that the model accounts for both tensile and creep behaviours of CWS.