核用真空阀门软钎焊工艺研究及应用

发布时间：2018-12-07 12:40

【摘要】：基于国家核电大发展的市场背景,相关的各个子行业都由此受益,核燃料提纯设备中必不可少的核用真空阀门市场巨大。波纹管组件软钎焊技术一直是困扰核用真空阀门生产的一项关键技术难题,多年来仍保持比较原始的手工凭经验操作的方式,当遇到批量订单生产时,技术及产能瓶颈影响按期交货。本课题基于产品设计、制造、检验及验收现有标准,采用理论分析与试验验证相结合的方法,开展了核用真空阀门软钎焊工艺研究。利用压力表、氦质谱检漏仪等对波纹管组件钎焊焊缝强度及密封性能进行了测试,研究出了一套真空阀门波纹管组件软钎焊工艺,钎料成分、焊接质量检验一次合格率和装配试验一次合格率均提高到了95%以上,达到了节能降耗的目的。主要内容如下:1、根据核燃料系统真空阀门软钎焊焊料S-Sn60PbB、S-Sn60PbSbB的主要成分构成完成了钎料试制,分析原材料、工艺流程、工具及温度等因素对钎料成分的影响,确定了钎料熔炼锡(Sn99.90AA)、铅(Pb99.990)重量配比为6:4,同时将制备工具材质改进为超低碳奥氏体不锈钢,解决了杂质成分超标的问题,完成了锡铅钎料制备工艺研究。2、通过分析不同助焊剂的成分及功用,确定助焊剂以精制松香为主,松香酒精溶液和氯化锌溶液配合使用。氯化锌溶液采用锌粉与37%的盐酸配制,松香酒精溶液采用精制松香粉末与浓度≥99.7%的分析纯乙醇CH3CH2OH配制。3、通过分析核用真空阀门波纹管组件焊缝结构,结合生产实践,研究出了两种软钎焊焊料规格,尺寸分别为3×16×R1.5及6×6×R2,能满足现有口径DN3~DN100范围内阀门波纹管组件软钎焊的生产需求,同时对焊料模具材质及结构进行了改进,保证了钎焊质量,提高了生产效率。4、通过分析及试验,完成了波纹管组件加工工艺研究,钎焊焊缝最佳间隙为30~50μm;分析波纹管组件钎焊工艺对钎焊质量的影响,完成钎焊工艺及工装研究,产品装配试验一次合格率由70~80%提高到95%以上。5、收集并整理了核用真空阀波纹管组件软钎焊典型质量问题,完成了原因分析,明确了处理办法,制定了预防措施。
[Abstract]:Based on the market background of the great development of national nuclear power, all the related sub-industries benefit from it. The nuclear vacuum valve market, which is indispensable in the nuclear fuel purification equipment, is huge. Corrugated tube assembly soldering technology has been a key technical problem that puzzles the production of nuclear vacuum valves. For many years, it still maintains a relatively primitive manual operation by experience, when it comes to mass order production, Technical and capacity bottlenecks affect timely delivery. Based on the existing standards of product design, manufacture, inspection and acceptance, the soft brazing technology of nuclear vacuum valve is studied by combining theoretical analysis with test verification. Using pressure gauge, helium mass spectrometry leak detector and so on, the weld strength and sealing performance of brazing of bellows assembly were tested, and a set of soft brazing technology and solder composition of bellows assembly of vacuum valve were studied. The qualification rate of welding quality inspection and assembly test is increased to more than 95%, and the purpose of saving energy and reducing consumption is achieved. The main contents are as follows: 1. According to the main composition of the solder S-Sn60PbBU S-Sn60PbSbB for vacuum valve of nuclear fuel system, the effects of raw materials, technological process, tools and temperature on the composition of solder are analyzed. The solder smelting tin (Sn99.90AA), lead (Pb99.990) weight ratio is 6: 4, and the material of the preparation tool is improved to ultra-low carbon austenitic stainless steel, which solves the problem that the impurity composition exceeds the standard. The preparation process of tin lead solder was studied. 2. By analyzing the composition and function of different flux, it was determined that the flux was mainly refined rosin, the rosin alcohol solution and zinc chloride solution were used together. Zinc chloride solution was prepared with zinc powder and 37% hydrochloric acid, and rosin alcohol solution with refined rosin powder and analytical pure ethanol CH3CH2OH with concentration 鈮，

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