Research On Welding Technology And Quality Control For Sidewall Of High Speed Train Body

High speed train as a modern vehicle, its safety, fast, energy saving, green environmental protection is an important reason for its fast development. The 380 kilometers per hour high-speed train produced by Bombardier Sifang company is a new generation of high-speed train in China. The aluminum alloy side wall of the high speed train has a very important role for the whole vehicle structure, it must be a skilled welding process to ensure the reliability and stability of its quality. Therefore, it is very important to research the welding manufacturing process of aluminum alloy side wall of the vehicle.Through the analysis of the side wall structure, this paper describe a clear design scheme for the the side wall fixture design. And the hydraulic pressure system is adopted system instead of the screw clamp, that not only can improve the production efficiency, but also guarantee the stability of the clamping system. By the comparative study of weld forming, welding heat input, the mechanical properties of the joints and welding efficiency in the ways of TIG, single wire MIG and double wire MIG, double wire MIG is identified as the first choice of side wall welding production method. In order to control the welding deformation, the reasons for welding deformation are analyzed according to the side wall structural characteristics and assembly welding process. The measures of reducing the welding deformation by the method of the anti deformation method is proposed. That not only meet the technical requirements of the side wall, but also reduce the use of the flame adjustment effectively. It has important reference value for improving the quality control of the side wall. These work will be an important reference for improving the sidewall welding quality.In order to control the welding quality, this paper also describes the quality control method of sidewall in the high speed train, and give a detail discussion for the quality control points of the three stages of the welding process,namely,preweld,welding and postweld. And the key points of the WPQR are deeply studied, the tensile test, bending properties, macro and micro metallographic test results of WPQR for 6mm welding seam are listed. The results show that the indexes of process evaluation met the standard of ISO15614. This paper provides a reliable quality assurance method for the follow-up project and other similar high iron wall welded structure.