Hardfacing coatings are widely used on the surfaces of parts subjected to drastic loadings. Norem02 alloy, Fe-based, is used in PWR nuclear power plants on valves seating surfaces. Its microstructure consists of a dendritic austenite structure with ferrite islets and carbides. This work tends to demonstrate that for this alloy, metallurgical evolution during the welding process has very little influence on mechanical properties. Tensile behaviour was characterised and completed by dilatometry tests in welding process temperature range until 1000°C, in order to identify an elastoplastic model with non linear kinematic hardening rule. Temperature, displacements, distorsions and residual stresses were measured during the PTAW process and used to identify an equivalent thermal loading by solving an inverse problem. Finally, the numerical simulation of the whole process using the EDF R and D FEM software Code_Aster is presented. Predicted temperatures are consistants with experimental ones. In the same way, predicted displacements, residual distorsions and residual stresses at the end of the cooling phase are close to experimental measures, validating the modelisation strategy presented in this work.
