反应釜毕业设计外文翻译.doc

Welding Simulation of Cast Aluminium A356 X-T. Pham*, P. Gougeon and F-O. Gagnon Aluminium Technology Centre, National Research Council Canada Chicoutimi, Quebec, Canada Abstract Welding of cast aluminium hollow parts is a new promising technical trend for structural assemblies. However, big gap between components, weld porosity, large distortion and risk for hot cracking need to be dealt with. In this paper, the MIG welding of aluminium A356 cast square tubes is studied. The distortion of the welded tubes was predicted by numerical simulations. A good agreement between experimental and numerical results was obtained. Introduction Aluminium structures become more and more popular in industries thanks to their light weights, especially in the automotive manufacturing industry. Moreover, welding of cast aluminium hollow parts is a new promising technical trend for structural assemblies [1-3]. However, it may be very challenging due to many problems such as big gap between components, weld porosity, large distortion and risk for hot cracking [4,5]. Due to local heating, complex thermal stresses occur during welding; residual stress and distortion result after welding. In this paper, the aluminium A356 cast tube MIG welding is studied. The software Sysweld [6] was used for welding simulations. The objective is to validate the capability of this software in predicting the distortion of the welded tubes in the presence of large gaps. In this work, the porosity of welds was checked after welding using the X-ray technique. The heat source parameters were identified based on the weld cross-sections and welding parameters. Full 3D thermal metallurgical mechanical simulations were performed. The distortions predicted by the numerical simulations were compared to experimental results measured after welding by a CMM machine. Experiments Experimental setup Two square tubes are made of A356 by sand casting and then machined. They are assembled by four MIG welds, named W1 to