【正文】 [7]李炯輝. 焊接金相分析基礎(chǔ)與金相圖譜[Ｍ]. 北京:機械工業(yè)出版社,2009.[8]劉會杰. 焊接冶金與焊接性[Ｍ]. 北京: 機械工業(yè)出版社,2007附 錄2Now in the project many ponents need to work in the high temperature either the low temperature, the corrosive medium, the electromagnetic field or the radioactive environment, the nonferrous metal material39。s overall performance even surpasses the sole metal structure. The heterogeneous material39。s day by day, has the broad application prospect, in recent years in astronautics, the petroleum chemical industry, the utility boiler, the nuclear power, the shipbuilding and other domains obtained more and more widespread application. Because the lowcarbon steel and the copper and the alloy material have the fine performance, enables them to obtain the widespread application in the industrial engineering, this inevitably must face to these two different metal connection question, the welding is the engineerig material connection one main method, therefore carries on the lowcarbon steel alloy material and the copper alloy the welding to have in the project application aspect the significant significance, may display the lowcarbon steel alloy and the copper alloy material high performance fully, receives “makes the best use of things” effect, but did not have one method to the present to be able to meet the requirements. This topic attempt uses the tungsten inert gas arc welding (TIG) to the lowcarbon steel, the copper heterogeneous material to carry on the welding, provides the theory basis and the experiment foundation for the lowcarbon steel and the copper heterogeneous material welding39。 however, iron and copper atoms, Atomic radii, lattice constant, chemical properties, are more recent, is beneficial for welding. Can be seen from the physical experiment, steel and copper or copper alloy microstructure of dissimilar metal welds, mainly by α + ε phase position, atoms not fusion gap does not exist. This can indicate, steel and copper or copper alloy, can take a variety of methods of welding. Late in the crystallization of these liquid crystals were distributed in the form of α solid copper grain boundaries, and sever the link between solid grains, the binding force between the grains to be weakened so that the plastic weld metal dropped significantly, coupled with the copper and steel linear expansion coefficient and the shrinkage of large differences in the cooling weld solidification process will have a greater welding stress. Therefore, when copper weld strength steel, plastic dropped significantly, and in the welding of the stress on the fragile joints of a hot crack sites, but as long as a reasonable implementation of the welding process, mastering welding technology, can be satisfied with the Copper steel welded joints.copper and stainless steel welding technologyTIG welding of copper can obtain high quality of welded joints with arc energy concentration, the protective effect is good, narrow heataffected zone, the advantages of flexible operation, this method has bee a copper and copper alloy welding method, the most widely used one Species, particularly suitable in small pieces of sheet metal and welding and repair welding.TIG Welding almost can be used for all steel, nonferrous metals and alloys, welding, ideal for chemically reactive metals and their alloys. Commonly used in stainless steel, high temperature alloys, aluminum, magnesium, titanium and their alloys and difficult to dissolve in lively metal (such as zirconium, molybdenum, niobium, etc.) and welding of dissimilar metals. TIG Weld welded easy control, easy to implement singlesided welding forming, mainly used for thin plate welding or backing plate for welding. Pulse TIG welding is particularly suitable for allposition welding sheet and pipe butt weld. However, because current tungsten, arc power limited capacity is limited, resulting in weld penetration depth, welding speed, TIG welding generally only used for welding thickness in 6mm following39。 on the contrary, the infiltration of serious, leading along the grainboundary fracture of macrocracks.4﹑Conclusion This thesis by TIG Welding process on copper and steel welding of dissimilar materials, As copper and steel welding of dissimilar material for the development of theoretical basis and experimental basis. (1)Copper and steel of physical properties and chemical position varies greatly, copper steel weld is easy to produce a lot of defects such as cracks, pores fussion, etc, but as long as the implementation of reasonable welding process, welding operations technical mastery, will still be able to obtain satisfaction of coppersteel welded joints. (2) Through welding inspection, welds with good performance, and prove that welding process and its arguments are reasonable. (3)Metallographic examination, the internal organization of uniform welds。 copper and steel weld line straight, no holes, and Cu And Fe Each other to a certain extent, the fusion zone for metallurgical bine. References[1]Liu Zhongqing. Welding of dissimilar materials [M]. Beijing: Science Press, 1990. [2]Zhouzhenfeng. Welding metallurgy and metal welding [M]. Beijing: Machinery Industry Press, 1988. [3]The Chinese Mechanical Engineering Society. Welding Manual (2) [M]. Beijing: Machinery Industry Press, 1992. [4]LAB has Di. Nonferrous metal welding [M]. Beijing: Machinery Industry Press, 1987. [5]In Yongfu, DeSheng Zhang. Metal welding materials [M]. Beijing: Machinery Industry Press, 1995. [6]Huang Zhe. Welder Manual [M]. Beijing: Machinery Industry Press, 1991. [7]Lijionghui. Welding metallographic analysis and metallographic base map [M]. Harbin: Harbin Institute of Technology Press, 1993. [8]Liuhuijie. Welding metallurgy and weldability [M]. Beijing: Machinery Industry Press,