Prediction and Control of Residual Stresses and Distortion in HY-130 Thick Pipe Weldments

摘要

In order to validate existing techniques for computer simulation of the welding process, an experiment is designed and carried out in which seam and girth welds are produced on a high strength steel cylinder. Fabrication of the HY-130 cylinder, selection of welding parameters for the seam and girth welds, and the selection and arrangement of instrumentation are described. The theoretical background of finite element computer simulation of heat flow in weldments as well as techniques for axisymmetric finite element analysis of thermal stress and metal movement during welding are discussed. Finite element representation of weldment geometry for heat flow and stress analysis is presented. Metallurgical properties of the HY-130 cylinder seam weld are presented in the form of photo-micrographs and electron scan micrographs. Temperature, strain, and radial distortion are measured at various locations on the HY-130 cylinder and the measured values are compared in tabular and graphical form with those values predicted by use of the heat flow and stress analysis programs. Excellent agreement is achieved between measured and analytically predicted temperature distributions, but only qualitative agreement is shown for strains and radial distortion. (Author)