Effect of Weld Bead Shape on the Fatigue Behavior of GMAW Lap Fillet Joint in GA 590 MPa Steel Sheets

Abstract

Abstract:In this study, the effect of weld bead shape on the fatigue strength of lap fillet joints using the gas metal arc welding (GMAW) process was investigated. The base material used in the experiment was 590 MPa grade galvanealed steel sheet with 2.3 mm and 2.6 mm thickness. In order to make the four types of weld beads with different shapes by factors such as length, angle, and area, the welding process, wire feeding speed, and joint shape were changed. The stress-number of cycles to failure (S-N) curve and fatigue strength were obtained from the fatigue test for four types of weld bead, and the cause of the fatigue strength difference was clarified through the analysis of the geometrical factors, such as length, angle, and area of the weld bead. In addition, the relationship between weld bead shape and fatigue strength was discussed.

Effect of Porosity on the Fatigue Behavior of Gas Metal Arc Welding Lap Fillet Joint in GA 590 MPa Steel Sheets

“…The fatigue test was carried out using a specimen with similar weld beads to minimize the effect of weld bead shape on the fatigue test. It was reported that the fatigue behavior varies depending on the bead shape of the weld [11]. The weld bead size was measured using the length parameter shown in Figure 10 according to the types of weld defects.…”

“…Fatigue fracture propagates from the root to the top of the plate when fatigue cracking occurs at the root and when fatigue cracking occurs at the weld toe, the fatigue fracture propagates down to the weld toe of the bottom plate. Hwang et al [11] reported that fatigue fracture propagated from the root to the top of the plate when fatigue cracks occurred at the root and fatigue crack propagated down to the weld toe of the bottom plate when fatigue cracks occurred at the weld toe. The applied load used for the measurement of static and fatigue strength can induce a very complicated distribution of normal and shear stresses in the lap joint [20][21][22].…”

“…At higher loads between 122 and 366 MPa, the effect of the secondary bending moment at the weld root increases. At lower loads below 92 MPa, the influence of the secondary bending moment becomes relatively smaller and the location of the stress concentration changes from the weld root to weld toe [7,11].…”

“…Feng et al [10] studied the fatigue behavior of welding parts via the arc welding of lap fillet joint for DP 600 MPa grade steel. Hwang et al [11] investigated the fatigue behavior of lap fillet weld joints using three welding processes-tandem MAG, direct current (DC) and DC pulse-for a galvanealed (GA) 590 MPa grade ferrite-bainite (FB) steel sheet. Kim et al [12] investigated the effect of weld bead shape on weld fatigue strength using the tandem MAG welding process for GA 590 MPa steel sheets.…”

Real-Time Weld Quality Prediction Using a Laser Vision Sensor in a Lap Fillet Joint during Gas Metal Arc Welding

“…Therefore, the weld lines in the chassis parts affect the overall performances of the chassis parts. Additionally, the geometry of the weld bead has a dominant influence on the mechanical performance of the chassis parts, that is, on their tensile strengths and fatigue characteristics [5][6][7][8][9]. The bead geometry is composed of five parts, including the weld face, root, toe, leg, and throat.…”