永久型阴极板导电杆铜—钢异种金属连接工艺及性能分析
发布时间：2018-08-02 18:08
【摘要】：永久型阴极板铜电解技术是一种高效绿色的新型铜电解技术。此种技术的重要特点是将传统方法中只能使用一次的电解始极板替换为可以反复使用的不锈钢阴极板。由于传统电解方法需要对工艺生产中种板加工系统和始极板剥离系统投入大量的人力和物力,而永久型阴极板铜电解技术则恰好省略了这两大系统,因而其生产成本更低,生产效率更高。永久型阴极板铜电解技术因其效率高,寿命长,产量高,绿色环保特别适合优质电解铜大批量、大规模的生产,所以其成为了目前全球铜电解技术的主要发展趋势,也成为了我国当前被大型铜电解厂和在建铜电解工程所更换和引进的主流技术。阴极板导电杆作为此项新型技术的关键部件,在我国目前还没有出现完全自主和广泛使用的结构设计和制造工艺,仍需要大量进口。因此,实现阴极板导电杆国产化的工艺与制造具有重要的工程与经济意义。由于永久型阴极板导电杆一般采用钢铜包覆结构,焊缝处于结构内部,其结合界面具有不可见性,而且铜和钢物理性能相差较大,在焊接过程中容易产生变形、裂纹等焊接缺陷,因此使用传统的焊接工艺很难适应此种特殊结构的连接。高频感应钎焊具有焊接温度较低,热源可控性强,内部焊缝的热源可达性好,而且钎料中的合金元素能有效避免焊接缺陷产生等优点。所以本文提出了采用高频感应钎焊的方法进行永久型阴极板导电杆的模拟钎焊试验。针对永久型阴极板导电杆的模拟试验,首先,本文选用Sn-Cu系二元共晶钎料作为实验所用钎料,并在焊接前在不锈钢工件的施焊表面进行钎料的预置涂敷;其次,本课题共设计十八组工艺试验,主要分为五大部分,其中涉及加热电流、中停时间等五个重要的工艺参数并在其中涉及两种工件类型;然后,再利用光学显微镜,扫描电子显微镜(SEM),能谱仪(EDS),X射线衍射仪(XRD)分析研究了不同工艺参数下形成钎焊接头的微观组织、物相种类及元素分布,同时采用智能金属导体电阻率仪、电子万能试验机和显微硬度计对铜-钢焊接接头的导电性能、硬度、强度等各项性能进行了检测,通过不同试样各项性能的不同反映出试样在化学成分、组织结构上对接头性能的影响以及实验工艺对接头性能造成的差异。通过光学显微镜,扫描电子显微镜和能谱仪的分析结果可得,第一种工件在合理工艺参数下焊后钎缝无明显的焊接缺陷且界面清晰;接头可明显分为铜侧反应扩散层、焊缝中间层和钢侧反应扩散层;铜侧反应扩散层的厚度均大于钢侧反应扩散层的厚度;第二种工件为铜钢包覆模拟工件,此类工件焊后钎缝平整无缺陷;接头处只含有一个反应扩散层,此反应扩散层与铜侧母材无明显界面区分,与不锈钢侧母材的界面清晰明显;焊接时由于包覆结构,工件内部热量集中,预置锡层完全扩散至铜侧母材中。综合钎焊接头组织形貌、元素分布、物相组成和试样导电性能检测结果可得,影响试样接头导电性能的原因主要有两个:第一,加热电流越大,加热时间越长,保温时间越长,即工件的焊接热输入过大,试样的导电性能则会出现下降趋势,这主要是由于工件焊接时,长时间处于高温条件下Cu与Sn会生成Cu3Sn,此铜锡化合物会对导电过程中载流子的定向移动速度产生阻碍,导致试样导电率的下降;第二,接头缺陷越少,致密性越好,导电性能越好,这主要是由于接头连续性不好,接触表面连接情况不均一影响电流在高低电势的流动。通过接头强度接头硬度的检测结果可得,第二类工件的接头拉伸强度明显优于第一类工件的接头拉伸强度,第二类工件的接头硬度也高于第一类工件的接头硬度,这说明包覆结构会使焊接时的热量在内部较集中,导致铜锡钢进行了充分的冶金反应并且生成了较多类似Cu3Sn的脆硬相。综合以上试验及检测结果,本文获得的最佳工艺参数能够得到焊缝成形美观、连接强度优良、导电性能良好的铜-钢钎焊接头。
[Abstract]:The permanent cathode plate copper electrolysis technology is a new type of high efficiency and green copper electrolysis technology. The important feature of this technology is to replace the electrolytic initial plate which can only be used once in the traditional method as the stainless steel cathode plate which can be used repeatedly. Because the traditional electrolysis method needs the processing system of the seed plate and the peeling system of the beginning plate in the process production. The permanent cathode plate copper electrolysis technology has omitted the two systems, thus the production cost is lower and the production efficiency is higher. The permanent cathode plate copper electrolysis technology has high efficiency, long life, high output, green environmental protection especially suitable for large quantity of electrolytic copper, so it is produced in large scale. As the main development trend of the current global copper electrolysis technology, it has also become the mainstream technology for the replacement and introduction of the large copper electrolysis plant and the copper electrolysis project in China. As the key component of this new technology, the cathode plate conductance pole has not yet appeared in our country, which is fully Autonomous and widely used. Therefore, it is still necessary to import a lot of materials. Therefore, it is of great engineering and economic significance to realize the process and manufacture of the homemade of the cathodic plate conductance rod. As the permanent cathode plate guide rod is usually covered with steel and copper cladding structure, the weld is inside the structure, its bonding interface is invisible, and the physical properties of copper and steel are quite different, and welding in welding. It is easy to produce welding defects such as deformation and crack in the process, so it is difficult to adapt to the connection of this special structure with the traditional welding process. High frequency induction brazing has the advantages of low welding temperature, strong controllability of heat source, good heat source of the internal weld, and the alloy elements in the solder can effectively avoid welding defects. In this paper, the simulation brazing test of permanent cathodic plate conductance rod is carried out by high frequency induction brazing. For the simulation test of permanent cathode plate conductance rod, first of all, the Sn-Cu two element eutectic solder is used as the filler of the experiment, and the preset coating on the welding surface of the stainless steel workpiece is applied before the welding. Secondly, we have designed eighteen groups of process tests, which are divided into five parts, including five important process parameters, such as heating current and mid stop time, and involving two kinds of workpiece types. Then, the different processes are analyzed by optical microscopy, scanning electron microscope (SEM), EDS, and X ray diffractometer (XRD). The microstructure, phase type and element distribution of the brazed joint are formed under the parameters, and the electrical properties, hardness and strength of the copper steel welded joint are detected by the intelligent metal conductor resistivity instrument, the electronic universal testing machine and the microhardness tester, and the sample in chemistry is reflected by the different properties of different samples. The influence of the composition and structure on the joint properties and the difference between the experimental process and the joint performance. Through the optical microscope, the scanning electron microscope and the analytical results of the energy spectrometer, the first workpiece has no obvious welding defects and the interface is clear under the reasonable process parameters, and the joint can be clearly divided into the copper side reaction expansion. The thickness of the reaction diffusion layer on the copper side is larger than the thickness of the reaction diffusion layer on the steel side, the thickness of the reaction diffusion layer on the copper side is greater than the thickness of the reaction diffusion layer on the steel side. The second workpiece is coated with copper and steel, and the joint is smooth and smooth after welding. The joint is only containing a reaction diffusion layer, and the reaction diffusion layer has no obvious interface distinction with the copper side material. The interface of the stainless steel side is clear and obvious; the coating structure and the internal heat of the workpiece are concentrated in the welding. The prepositioned tin layer diffuses completely to the copper side material. The microstructure of the joint, the distribution of elements, the composition of the phase and the test result of the conductivity of the sample can be obtained. There are two main reasons that affect the conductivity of the joint. The longer the heating time is, the longer the heating time is, the longer the heat preservation time is, that is, the heat input of the workpiece is too large and the conductivity of the sample will decline. This is mainly because the Cu and Sn will generate Cu3Sn for a long time under high temperature, and the copper tin compound will produce resistance to the directional moving speed of the carrier in the conduction process. Second, the less defects of the joint, the less the defects, the better the compactness and the better the electrical conductivity, which is mainly due to the poor continuity of the joint and the inhomogeneous contact of the contact surface on the flow of the high and low potential. The tensile strength of the joint strength of the second kinds of workpiece is clear by the result of the hardness of joint strength joint. The tensile strength of the joint of the first kind is superior to that of the first kind, and the joint hardness of the second kind of workpiece is also higher than the hardness of the first kind of workpiece. This indicates that the coating structure will make the heat of the welding more concentrated inside, leading to the full metallurgical reaction of the copper tin steel and the formation of more like Cu3Sn like brittle hard phases. The results show that the copper-steel brazed joint with beautiful weld shape, excellent bonding strength and good conductivity can be obtained by the optimum process parameters obtained in this paper.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG457.1
[Abstract]:The permanent cathode plate copper electrolysis technology is a new type of high efficiency and green copper electrolysis technology. The important feature of this technology is to replace the electrolytic initial plate which can only be used once in the traditional method as the stainless steel cathode plate which can be used repeatedly. Because the traditional electrolysis method needs the processing system of the seed plate and the peeling system of the beginning plate in the process production. The permanent cathode plate copper electrolysis technology has omitted the two systems, thus the production cost is lower and the production efficiency is higher. The permanent cathode plate copper electrolysis technology has high efficiency, long life, high output, green environmental protection especially suitable for large quantity of electrolytic copper, so it is produced in large scale. As the main development trend of the current global copper electrolysis technology, it has also become the mainstream technology for the replacement and introduction of the large copper electrolysis plant and the copper electrolysis project in China. As the key component of this new technology, the cathode plate conductance pole has not yet appeared in our country, which is fully Autonomous and widely used. Therefore, it is still necessary to import a lot of materials. Therefore, it is of great engineering and economic significance to realize the process and manufacture of the homemade of the cathodic plate conductance rod. As the permanent cathode plate guide rod is usually covered with steel and copper cladding structure, the weld is inside the structure, its bonding interface is invisible, and the physical properties of copper and steel are quite different, and welding in welding. It is easy to produce welding defects such as deformation and crack in the process, so it is difficult to adapt to the connection of this special structure with the traditional welding process. High frequency induction brazing has the advantages of low welding temperature, strong controllability of heat source, good heat source of the internal weld, and the alloy elements in the solder can effectively avoid welding defects. In this paper, the simulation brazing test of permanent cathodic plate conductance rod is carried out by high frequency induction brazing. For the simulation test of permanent cathode plate conductance rod, first of all, the Sn-Cu two element eutectic solder is used as the filler of the experiment, and the preset coating on the welding surface of the stainless steel workpiece is applied before the welding. Secondly, we have designed eighteen groups of process tests, which are divided into five parts, including five important process parameters, such as heating current and mid stop time, and involving two kinds of workpiece types. Then, the different processes are analyzed by optical microscopy, scanning electron microscope (SEM), EDS, and X ray diffractometer (XRD). The microstructure, phase type and element distribution of the brazed joint are formed under the parameters, and the electrical properties, hardness and strength of the copper steel welded joint are detected by the intelligent metal conductor resistivity instrument, the electronic universal testing machine and the microhardness tester, and the sample in chemistry is reflected by the different properties of different samples. The influence of the composition and structure on the joint properties and the difference between the experimental process and the joint performance. Through the optical microscope, the scanning electron microscope and the analytical results of the energy spectrometer, the first workpiece has no obvious welding defects and the interface is clear under the reasonable process parameters, and the joint can be clearly divided into the copper side reaction expansion. The thickness of the reaction diffusion layer on the copper side is larger than the thickness of the reaction diffusion layer on the steel side, the thickness of the reaction diffusion layer on the copper side is greater than the thickness of the reaction diffusion layer on the steel side. The second workpiece is coated with copper and steel, and the joint is smooth and smooth after welding. The joint is only containing a reaction diffusion layer, and the reaction diffusion layer has no obvious interface distinction with the copper side material. The interface of the stainless steel side is clear and obvious; the coating structure and the internal heat of the workpiece are concentrated in the welding. The prepositioned tin layer diffuses completely to the copper side material. The microstructure of the joint, the distribution of elements, the composition of the phase and the test result of the conductivity of the sample can be obtained. There are two main reasons that affect the conductivity of the joint. The longer the heating time is, the longer the heating time is, the longer the heat preservation time is, that is, the heat input of the workpiece is too large and the conductivity of the sample will decline. This is mainly because the Cu and Sn will generate Cu3Sn for a long time under high temperature, and the copper tin compound will produce resistance to the directional moving speed of the carrier in the conduction process. Second, the less defects of the joint, the less the defects, the better the compactness and the better the electrical conductivity, which is mainly due to the poor continuity of the joint and the inhomogeneous contact of the contact surface on the flow of the high and low potential. The tensile strength of the joint strength of the second kinds of workpiece is clear by the result of the hardness of joint strength joint. The tensile strength of the joint of the first kind is superior to that of the first kind, and the joint hardness of the second kind of workpiece is also higher than the hardness of the first kind of workpiece. This indicates that the coating structure will make the heat of the welding more concentrated inside, leading to the full metallurgical reaction of the copper tin steel and the formation of more like Cu3Sn like brittle hard phases. The results show that the copper-steel brazed joint with beautiful weld shape, excellent bonding strength and good conductivity can be obtained by the optimum process parameters obtained in this paper.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG457.1
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4 石s，
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