STUDY OF RESIDUAL STRESSES GENERATED IN P91 STEEL WELDED BY FCAW/MCAW PROCESSES

Components exposed to high temperature and pressure fields, such pipelines of petrochemical industry, have strict strength requirements, good creep resistance, stable microstructure and a set of properties that prevent premature and catastrophic failure. The knowledge of residual stress arising from the welding processes is extremely important because the mechanical properties of the welded components are not only determined by the microstructures present in the joint, but also by the heterogeneous residual stresses introduced during the thermal cycle in welding processes. The aim of this work is the study of residual stresses generated of ASTM P91 steel-pipe welded by Metal Cored Arc Welding & Flux Cored Arc Welding (MCAW/FCAW) processes. Residual stresses were analysed by X-ray diffraction technique with sin2 psi method, and presenting tensile behaviour with higher magnitude at the weld metal of root region.