镀铬技术在活塞环槽表面处理中的应用研究

发布时间：2018-02-01 06:04

本文关键词： 活塞环槽镀铬六价铬　出处：《大连海事大学》2014年硕士论文　论文类型：学位论文

【摘要】：船舶低速柴油机活塞环槽在高温、高压、腐蚀、摩擦等工况下,工作寿命极易受到影响。镀铬技术在活塞环槽表面生成一层硬度较高的镀铬层,可以提高环槽表面的耐高温高压、耐腐蚀磨擦性能,所以在活塞环槽表面处理中得到普遍应用。大连迪施船机有限公司在活塞制造及翻新过程中采用滚镀镀铬技术处理活塞环槽表面。在生产过程中,曾经出现过电镀质量问题。确定原因是准备翻新的旧活塞在进入电镀槽之前未清洁彻底,金属杂质进入镀液,通过共用的镀液循环进入新活塞的电镀槽,最终使新活塞环槽镀铬层出现气孔,导致产品返工。本论文通过实验检验大连迪施实际生产中的镀液配比是否合理。同时,确认镀液对主要杂质的容忍度,为实际生产提供理论指导。所用电源为恒定电位仪,采用的是六价铬镀铬工艺,设定几种镀铬溶液,通过设计的镀层性能测试实验,确定镀层性能最为优良的镀液,然后对此镀液成分进行单因素实验,得到了最佳的六价铬镀铬的工艺参数：CrO3:220～270g/L,H2SO4:1.92g/L,CrO3/H2SO4=130:l。针对上述镀液,通过实验分析最易对镀层造成影响的几种杂质的含量范围,以便在生产实践中及时监测杂质含量,以免影响镀层效果。确定的镀液对于几种主要杂质的容忍度为：三价铬含量控制在4～8g/L,铁离子含量不得超过8g/L,铜离子含量不得超过8g/L,氯离子含量不得超过8g/L。在大连迪施实际生产中,改变了以前生产中翻新、新品镀液混用的生产流程。电镀槽改良为独立循环,同时根据上述实验数据加强镀液杂质监控,降低了电镀出现质量问题的几率,提高了生产效率。
[Abstract]:Under the conditions of high temperature, high pressure, corrosion, friction and so on, the working life of the piston ring groove of low speed marine diesel engine is easy to be affected. It can improve the high temperature and high pressure resistance and corrosion resistance of ring grooves, so it is widely used in the surface treatment of piston ring grooves. In the process of piston manufacture and renovation, Dalian Dish Shippers Co., Ltd. uses the technology of chrome plating to treat the surface of piston ring groove. There have been problems with electroplating quality. The reason is that the old piston that is ready to be renovated has not been cleaned thoroughly before entering the electroplating bath, the metal impurity enters the plating bath, and the electroplating tank of the new piston is circulated through the common plating bath. Finally, the new piston ring slot chrome plating layer blowhole, resulting in product rework. This paper tests whether the proportion of plating bath is reasonable in the actual production of Dish in Dalian. At the same time, it confirms the tolerance of the bath to the main impurities, and provides theoretical guidance for practical production. The power source used is a constant potential instrument. The hexavalent chromium plating process is adopted, and several kinds of chromium plating solution are set up. Through the test experiment of the coating performance, the best plating bath is determined, and then the single factor experiment is carried out on the composition of the plating bath. The optimum process parameters of hexavalent chromium plating are obtained: 1: CrO3: 220g / L H2SO4: 1.92g / L. In view of the above bath, the content range of several impurities which are most likely to affect the coating is analyzed through experiments, so that the impurity content can be monitored in time in the production practice of CRO _ 3 / H _ 2SO _ 4 / 130: l. The tolerance of the plating solution to several major impurities is determined as follows: trivalent chromium content is controlled at 4g / L and iron ion content should not exceed 8g / L. The copper ion content must not exceed 8 g / L, the chlorine ion content must not exceed 8 g / L. In the actual production of Dish in Dalian, the production process of renovation in previous production and mixed use of new product plating bath has been changed. The electroplating bath has been improved to independent circulation, and the impurity monitoring of plating bath has been strengthened according to the above experimental data. The probability of quality problem in electroplating is reduced, and the production efficiency is improved.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U664.121.1

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