Prestressed Welding Technology Applied Research On The Locomotive Body Skin

Along with the development of our country's locomotive & rolling stock industry, the requirement of locomotive's exterior quality is becoming higher and higher besides the much higher requirement of locomotive's durability and reliability. However, because of the lower technological level in controlling the distortion of thin steel plates during welding, the side wall skin of locomotive body is thus caused uneven. The flatness at some individual positions even reaches 5 mm/m2 so that the poor quality of locomotive's exterior has not been solved radically for a long time.The pre-stress welding technology is an effective means of technology to control welding distortion and welding stress of thin steel plates. It is a kind of new technology developed according to "Thermal Expansion" property of metal materials, metal welding stress and distortion theory. This thesis is just taking Dongfeng 4D type diesel locomotive manufactured by Dalian Locomotive & Rolling Stock Works as an example to put forward a technological scheme of skin's pre-stress welding according to the fundamental theory of welding stress and distortion and on the basis of further analysis on the larger welding distortion caused by the original welding technology.The application of the skin's pre-stress welding technology can remarkably improve the flatness of locomotive side wall skins. The flatness can meet the design requirement of less than 2 mm/m2, so that the exterior quality of locomotive has been improved. This has supplied a gap in terms of diesel locomotive skin pre-stress welding technology in China, got an advanced level in manufacturing diesel locomotive skins domestically and basically reached the advanced level in the world. The implementation of this technology can sufficiently improve the production efficiency and the material & energy sources consumption can be saved. The economic benefit is very considerable.