【作者】 杨兵兵；

【导师】 范志康；

【作者基本信息】 西安理工大学 ， 材料学， 2007， 硕士

【摘要】 铸造叶轮是造船、电力、制药、泵阀、交通运输等行业大型设备上的关键部件,对整个设备的综合性能起着举足轻重的作用。目前生产中对于复杂整体叶轮铸造工艺还存在着一定的难度,因此对于叶轮铸造工艺的研究历来就是铸造行业的热门话题。本文通过对大型复杂叶轮铸造工艺的分析、研究,旨在探索一种经济、实用的熔模-砂型复合铸造工艺,使企业在现有的设备条件下,采用该工艺能够铸造出符合技术要求的叶轮铸件。本项研究根据叶轮铸件的结构特点,以轮缘的内径为界限将叶轮分为形状复杂的叶片和形状简单的轮毂轮辐两大部分。对于复杂的叶片部分,通过压型压制出单个叶片的熔模;借助设计的工装将单个叶片组焊成整体叶片部分的熔模;经过涂料制备出叶片部分的硅酸乙酯-水玻璃复合型壳;在熔模型壳外缘制备水玻璃砂套后,经过脱蜡,焙烧,得到整个叶片部分的熔模型壳。对于形状简单的轮毂、轮辐部分,根据轮毂、轮辐上下端面及叶片型壳部分的外形尺寸制备出木质模样、芯盒;通过浇冒口系统设计,利用水玻璃砂造(芯)型得到形状简单的轮毂、轮辐部分以及复合铸型的浇冒口系统的砂型铸型。在此基础上,以水玻璃砂套外缘为基准,将熔模型壳和砂型铸型两部分组合成熔模-砂型复合铸型。通过配料、感应电炉熔炼、浇注、氧乙炔火焰震动气割、化学清砂得到了ZG1Cr18Ni9Ti不锈钢叶轮铸件。通过外观检验、尺寸测量,表明铸造叶轮尺寸精度达到了CT4～CT5、粗糙度达到了Ra3.2～1.6;通过关键部位着色渗透探伤、超声波探伤,表明该叶轮无超出技术要求的裂纹、缩孔、缩松、夹杂等铸造缺陷;通过成份检验、力学性能测试证明该叶轮的化学成分、力学性能满足技术要求。结果表明:采用该熔模-砂型复合铸造工艺生产的大型复杂叶轮质量不仅达到了技术要求,满足了生产的需要,而且工艺稳定,生产成本较低。更多还原

【Abstract】 Casting impeller is a key component which is used for many large equipments, such as ship building, electricity, pharmaceuticals, pump and valves and transportation, etc. And it will play a decisive role in the whole equipment’s integrated performance. A certain difficulty for the complicated impeller’s casting craft still exists in the current production. So on this aspect research has always been a hot topic in the casting Industry. Based on the analysis and research for the large complicated impeller’s casting craft, the present study aims at exploring a kind of melting modules-sand mould composite casting process which is economical and practical, in order to meet specification under the current equipment condition.Based on the structure feature of impeller casting, the impeller is divided into two parts: the complex shape leaves and simple shape spoke and wheel hub. On the one hand, for the shape complex leaves, melting modules of single leaves was pressed by pressure type, and the single leaves group then was melted the melting module of the whole leaves by the aid of design. Silicone alternate - silicate glass compounded type shell was made by the paints. After the shell with silicate on the edge of the lamina was made, the whole blade’s melting was moduled by the dewaxing and roasting. On the other hand, for the simple shape’s spoke and hub, the wooden appearance and core box was made according to hub and spoke’s lower and upper end surface including outline size of leaves shell. The simple shape spoke and wheel hub was obtained by silicate glass sand core and riser system design, and the sand mould of composite casting’s riser system was used a same process. Based on the above research, the melting modules-sand mould composite casting was combined by melting modules shell and sand mould casting type. A set of modular sodium silicate sand is made as a benchmark. The ZG1Cr18Ni9Ti stainless steel impeller casting was gotten by batching, induction furnace melting, pouring, oxyacetylene flame shock OFC, and chemical cleaning.Through the appearance examination and size measure, the results showed that the sizeaccuracy of casting impeller achieved CT4~CT5, and the roughness achieved Ra3.2~1.6. The study by the key spots coloration seepage and the supersonic crack detection also showed the impeller had no defections such as crack, shrink hole, shrink and mixture. Moreover, the components check and the performance testing indicated this kind of impeller could satisfy the specification in chemical composition and mechanical performance.As a conclusion, this kind of impeller’s quality not only meets technical and production need, but also had a stable process and lower production cost.更多还原