Finite element analysis of residual stress in the welded zone of a high strength steel

Abstract

The distribution of the residual stress in the weld joint of HQ130 grade high strength steel was investigated by means of finite element method (FEM) using ANSYS software. Welding was carried out using gas shielded arc welding with a heat input of 16 kJ/cm. The FEM analysis on the weld joint reveals that there is a stress gradient around the fusion zone of weld joint. The instantaneous residual stress on the weld surface goes up to 800 ~ 1000 MPa and it is 500 ~ 600 MPa, below the weld. The stress gradient near the fusion zone is higher than any other location in the surrounding area. This is attributed as one of the significant reasons for the development of cold cracks at the fusion zone in the high strength steel. In order to avoid such welding cracks, the thermal stress in the weld joint has to be minimized by controlling the weld heat input.

Transverse and Longitudinal Stress Analysis in Reinforced Welded Oil Branched Pipes

“…Figure 3 shows the model meshing. There is a strong thermal gradient and stress in the vicinity of HAZ and this zone is of high importance [8,9]. Therefore, finer meshes were used in this zone.…”

“…This study required a large amount of calculations demanding a very specific system. Therefore, it adopted melting temperature method [9,12]. Convection heat transfer coefficient in central line was zero due to the symmetry of the line and was considered to be 15 (W.m 2 )/c in other surfaces.…”

“…Convection heat transfer coefficient in central line was zero due to the symmetry of the line and was considered to be 15 (W.m 2 )/c in other surfaces. Ambient temperature was assumed 18 o C [8,9,13,14]. In this study, a constant heat was applied in each pass which was proportional to welding time and the position of welded elements.…”

Análisis térmico de soldadura GTAW sobre placa de acero AISI 316L empleando el método de elementos finitos

“…La ecuación de difusión del calor en la que se basan los programas de AEF para realizar el análisis térmico de una soldadura se expresa de dos maneras [3,10]:…”

“…Estas modelaciones se realizan con software de elementos finitos especialmente desarrollados para aplicaciones en soldadura como el WELDSIM [1] o el SYSWELD [2], o mediante software comerciales de uso general como ANSYS [3][4][5], ABAQUS o COSMOS [6]. El empleo de un software de uso general trae consigo la necesidad de desarrollar metodologías y programas para la ejecución del análisis térmico de soldaduras.…”