Butt welding

About: Butt welding is a research topic. Over the lifetime, 7153 publications have been published within this topic receiving 44467 citations.

Study on dissimilar friction stir butt welding of AA7075-O and AA2024-T4 considering the manufacturing limitation

Abstract: In the present article, the effect of friction stir welding (FSW) parameters on the weldability and the characteristics of dissimilar weld of aluminum alloys, called AA2024-T4 and AA7075-O are investigated. A number of FSW experiments are carried out to obtain high-quality welds by adjusting the rotational and welding speeds. The weldability and blending of two materials are evaluated by using the macrostructural analysis to observe whether making a notch in a threaded cylindrical tool will lead to a better blend rather than the threaded taper tool or it will have no effects. The mechanical properties of the welds are studied through microhardness distribution and tensile tests. Furthermore, the microstructure analysis is performed to study the influence of the pin profile and the rotational speed on the grain size. Moreover, in the present study, one of the most major goals is to obtain high-quality welds by spending as little expenditure as possible. Therefore, it prevents using complicated and insupportable high welding speed equipments.

Three-dimensional finite element simulation of residual stresses in circumferential welds of steel pipe including pipe diameter effects

Abstract: In circumferential welding of a pipe component, it is often considered that axisymmetric model can provide a reasonable prediction of the residual stress distributions However, in general, the axisymmetric model cannot reproduce the traveling arc along circumferential welds and rapid change of residual stresses that can be observed in the overlapping region Moreover, it tends to overestimate the hoop residual stresses in circumferential welds Therefore, three-dimensional finite element (FE) model is essential for the accurate simulation of circumferential welding which can incorporate the three-dimensional effects This paper presents the three-dimensional FE simulation of circumferential butt welding of a steel pipe The thermo-mechanical model used as well as the simulation methodology is detailed, and the results are discussed In addition, parametric studies with inside radius to wall thickness ratio ranging from 100 to 1000 have been presented to investigate the effects of pipe diameter on residual stresses Axial and hoop residual stresses are plotted for the considered range of pipe diameters, and the differences are discussed

Erratum to: Multi-response optimization using the Taguchi-based grey relational analysis: a case study for dissimilar friction stir butt welding of AA6082-T6/AA5754-H111

Abstract: This paper presents a multi-response optimization process for dissimilar friction stir welding of AA6082/AA5754 aluminum alloys. An L9 orthogonal array was constituted for the experiments. Three welding parameters—tool shoulder diameter-to-pin diameter (D/d) ratio, tool rotational speed (TRS), and welding speed (WS)—were associated with tensile strength and elongation. An optimization process was started to determine the signal-to-noise (S/N) ratio. Grey relational analyses were performed utilizing the S/N ratio. According to the results of a series of analyses, the optimal welding condition was determined as 4 for D/d, 1,000 rpm for TRS, and 100 mm/min for WS. The analysis of variance results showed that all the welding parameters are statistically significant at 95 % confidence level. Additionally, the joint efficiency of welding fabricated at the optimal condition was compared for both AA6082 and AA5754. This revealed that the joint efficiency is 66 % for AA6082 and 92 % for AA5754.

Effects of pulse level of Nd-YAG laser on tensile properties and formability of laser weldments in automotive aluminum alloys

Abstract: Tensile properties and formability are important parameters in many applications. Being a lightweight material, aluminum is increasingly employed in the fabrication of automotive body panels. This study performs butt welding without filler metal on two frequently used automotive body panel aluminum alloys, 5754-O and 6022-T4E29. Welding is conducted using a Nd-YAG laser with a rectangular wave form having various pulse levels (ΔP) but a constant mean power of 1.5 kW. For both alloys, the results indicate that the travel speed required to achieve a successful butt joint increases as ΔP decreases. For a constant pulse level, the travel speed required for the higher Mg content 5754-O alloy (2.9 wt.% Mg) is approximately 2.5 times that of the lower Mg content 6022-T4E29 alloy (0.61 wt.% Mg). Additionally, it is shown that the tensile strength, percentage elongation and formability of both alloy weldments increase with decreasing ΔP level. In the 5754-O alloy, these trends are attributed primarily to the occurrence of magnesium evaporation during the welding process, microstructure refining, and porosity reduction in the resultant welds. However, for 6022-T4E29, the evaporation of Mg is not significant, and consequently, the variation in porosity is not great. These results are caused by a lower Mg content in the base metal. Therefore, the enhancement of the mechanical properties observed in the weldments is a result of a refinement of the weld microstructure.