Leak Analyze And Study On Defects Of Tig Weld Of Brass Tube-fin Oil Cooler

In this paper, the special leak problem of TIG weld of traces of Brass Tube-Fin Oil Cooler were studied. A study of reasons of leak of the TIG weld, of characteristics and Formation of pore of the TIG weld were made. Meanwhile we made a research and track of production process of Brass Tube-Fin Oil Cooler.The results show that there is pore in about 90% of the TIG weld of Brass Tube-Fin Oil Cooler which due to evaporation of zinc and influence of hydrogen. But the pore is stable and fine, it didn't cause leak of the TIG weld. The main reasons of leak of the TIG weld are lack of weld and special Macroporous, which are in the TIG weld. It was found out that there were many factors inimical to good weld by means of research and track of the production process of Brass Tube-Fin Oil Cooler, among which, the low assembling accuracy and improperly cleaned before welding are two essential factors.According to the diagnosis of production process of Brass Tube-Fin Oil Cooler, simulation experiments of lack of weld and special Macroporous were designed.The results show that dislocation, variable gap, grease and oxide film all caused lack of weld defect under a specified condition, but special macroporous wasn't appear. Using the theroy of thermal of arc and arc force to analyze the process of lack of weld caused by four factors, in order to explain the lack of weld in leaking samples. The most probable causes of process of special macroporous were also given.According to all the work, the production process of Brass Tube-Fin Oil Cooler was improved. By improving, part of the factors were cleard, and the production process was stabled. At last, the quality of the TIG weld of Brass Tube-Fin Oil Cooler was improved, and the pass-rate of the oil cooler was increased too.