Showing 3 results for Dissimilar Welding
R. Ghasemi, E. Heshmat Dehkordi, M. Shamanian,
Volume 2, Issue 1 (8-2016)
Abstract
In this study, microstructural features and mechanical properties of Incoloy 825-316L stainless steel dissimilar joints have been investigated. For this purpose, pulsed gas tungsten arc welding method was employed and 316L, Inconel 82 and Inconel 625 alloys were used as filler metal. First, specimens were cut. Pulsed gas tungsten arc welding was performed using peak and base currents of 220 A and 110 A, respectively. Microstructure of welded joints was studied using metallographic observations and energy dispersive spectroscopy (EDS) analysis. In order to evaluate the mechanical properties, tensile and microhardness measurements were done on the joints. In all specimens, dendritic and equiaxed and/or cellular growth of austenite phase was observed. Incoloy 625 weld metal had the finest dendritic structure. Tensile test results revealed the ductile fracture with a high percent of elongation for all specimens. The highest tensile strength and percent of elongation of 610 MPa and 48% were obtained for specimen welded using Inconel 625 filler metal. Inconel 625 and 316 stainless steel weld metals showed the highest and lowest microhardness with values of 232 HV and 224 HV, respectively.
A. Rabiezadeh, A. Afsari,
Volume 4, Issue 2 (1-2019)
Abstract
The purpose of this study was to examine the effect of adding Nano particles such as Nano Carbon Tube during Friction Stir Welding (FSW) on dissimilar Al alloy joints. More specifically, both FSW and Friction Stir Processing (FSP) were performed simultaneously to investigate the effect of adding Nano particles on mechanical properties and microstructure of the weld zone for joining AA5754-H22 and AA6063-T4aluminum alloys. Reliability of the joints was tested by non-destructive tests such as visual inspection, ultrasonic, and radiography. The global mechanical behaviors of dissimilar welds were similar to that of the base material. Important losses in ductility were also reported for dissimilar welds. Microstructural evaluation of fractured surfaces indicated that ductile fracture was the major mechanism of similar and dissimilar welds. We expected that the locks for dislocation moving would improve the mechanical properties of the weld zone. Also, the friction coefficient in the two-passes welded sample was about 30% lower than the friction coefficient of the base metal. On the bases of the wear resistance of hardness and the coefficient of friction, it was concluded that the wear resistance of the surface Nano-composite produced had also increased in the stir zone.
Gh. Khalaj, E. Asadian,
Volume 8, Issue 2 (1-2023)
Abstract
In this paper, the microstructure and mechanical properties of the plain carbon steel-bronze interface of explosive welding and rolling were investigated. Explosive connection was done at two stop distances and with two different thicknesses of explosive material. Rolling of the welded composite was done at both ambient and preheated temperatures of 300 °C and with a constant thickness reduction of 33.3%. The results showed that the wave interface of the steel-bronze connection includes different parts. By rolling, the connection interface was stretched and flattened and the vortex areas were compressed together and in some cases entered the steel field. The steel particles separated from the background along the wave crest and remained as isolated islands in the bronze background. On the other hand, in the areas near the vortex, a part of the bronze flying metal was caught under the wave and was observed as islands separated from the bronze background inside the steel. Porous areas were crushed and compressed as a result of rolling. The rolling force and temperature had partially removed the diffusion barriers and a metal bond had been formed between bronze and steel. During the connection, the voids and shrinkage pores were pressed together due to rolling and the separate borders were close to each other. Explosive joining and cold rolling had increased the hardness in the interface, and hot rolling has led to a decrease in the hardness in the interface. In the hardness test, the welding samples are arranged in the order of the highest impact energy. The effects of welding parameters remain after cold and hot rolling and the hardness rating does not change.
