| At present, our country's electrified railway has entered a stage of rapid development, and high-speed railway catenary technology has also been the focus of national development goals. Clevisend wedge-type clamp is a component of the electrified railway catenary,subject to production conditions,the parts can not use forging process and can only be obtained by casting means.While the products obtained by traditional sand casting have rough surface and low strength, which is difficult to meet the performance requirements.Due to the realization of high-precision complex molding,investment casting occupies a dominant position in the manufacture of high-end castings, and plays an important rolein the aviation,automotive railway and other industries.The purpose of this paper is to use the investment casting process to produce the performance requirements of the clevisend wedge-type clamp parts,mainly carried out the following research:The gateing system of clevisend wedge-type clamp and the best pouring parameters are determined.According to the structural characteristics of the parts, two different casting systems were designed. The casting and solidification process of the castings under different casting parameters are analyzed by using the casting simulation software MAGMA, to predict the possible shrinkage defects,and choose suitable pouring system with optimized pouring parameters according to the simulation results.The simulation results show that the two kinds of pouring systems have the best simulation results when the pouring temperature is 1600 ?,and the metal solution can fill the cavity smoothly, and the possibility of shrinkage and shrinkage after solidification is the lowest.Combined with the actual production of the factory,this paper choose a more post-processing post-processing as a casting process of casting system, pouring temperature of 1600 ?.The optimum content of the ingredients is determined.Under the laboratory conditions, the raw material components were optimized using the control variable method.The effects of the contents of three elements, C, Si and Mn on the microstructure and properties were studied, and the optimum content range was determined.The results show that when the C content is in the range of 0.15 ?0.24%, with the increase of C content,the size and distribution of ferrite and pearlite become uniform, the number of pearlite increases, the tensile strength, the yield.strength increases, the elongation decreases;When the Si content is in the range of 0.2 ? 0.8%,with the increase of Si content,organization is more uniform, tensile strength, yield strength, elongation decreased;When the Mn content is in the range of 0.3 ? 0.9%, with the increase of Mn content,the number of pearlite increased significantly, the size of the organization, the distribution becomes uniform, the grain has been refined, tensile strength, yield strength, elongation also increased.Combined with the actual production of the factory, determine the content range: carbon content of 0.18?0.24%,silicon content of 0.40?0.80%,manganese content of 0.70 ?1.10%.Using the experiment to determine the content of raw materials and pouring system,the investment casting process is determined from the wax mold preparation,shell preparation, melting pouring, heat treatment and other aspects.The quality of the castings produced by the program was tested and the results indicated that,the use of the investment casting process to produce clevisend wedge-type clamp to meet the technical requirements, with reasonable and feasible, can effectively guide the actual production. |
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