变极性脉冲酸洗电源及交流脉冲酸洗去除氧化皮研究

发布时间：2018-08-11 17:08

【摘要】：电解酸洗作为一种高效、清洁的钢材表面氧化皮去除技术,适用于各种形状及化学组成的钢材,能够彻底去除氧化皮的同时兼具抛光的效果。其中,阴阳极交替电解酸洗综合了阳极电解酸洗速度较快和阴极电解酸洗效果好的优点,用交流电或交变脉冲进行酸洗,已经受到越来越多的关注。而目前的酸洗电源在输出模式及控制精度、响应速度等方面存在不足,导致对电解酸洗过程及控制方面的研究较为缺乏。因此,研制一种高精度的变极性脉冲酸洗电源及对交流脉冲酸洗工艺及控制方面进行研究对提高酸洗效果具有重要意义。本文首先根据变极性脉冲酸洗电源的总体方案,完成了主电路及控制系统各部分的设计。经安装调试,所研制的变极性脉冲电源具有直流、直流脉冲、交流对称及交流不对称脉冲四种电流输出模式,且具有较高的控制精度及较快的响应速度,能够满足各种电解酸洗工艺需求,较目前的酸洗电源有较大优势。对电解酸洗过程进行了研究。搭建电解酸洗实验平台,采用单变量控制方法研究交流对称脉冲电流波形条件下电流密度和脉冲频率对实际酸洗效果的作用规律,通过对电特性曲线的测试分析和酸洗表面微观形貌的观察发现:脉冲频率一定时,电流密度越大,酸洗效率越高,但电流过大会导致试样表面出现过腐蚀,不利于形成良好的表面质量;电流密度一定时,酸洗过程存在与电流密度相对应的最佳脉冲频率,在最佳频率条件下可获得较快的处理速度和较好的表面质量。通过多组实验,获得了交流对称脉冲最佳频率随电流密度变化的关系曲线。对交流脉冲酸洗去除氧化皮的机理及酸洗过程控制策略进行了探索。分析阴阳极电解作用时分别发生的电化学反应及试样表面状态的变化过程,从理论上解释了在最佳频率下可获得较快处理速度及较好表面处理质量的原因。对交流脉冲酸洗控制策略进行了研究,提出了实时控制和改善酸洗过程的思路。
[Abstract]:Electrolytic pickling, as an efficient and clean technology for removing the oxide layer on steel surface, is suitable for steel with various shapes and chemical composition. It can completely remove the oxide layer and also has the effect of polishing. Among them, alternating anode and anode electrolytic pickling has been paid more and more attention by combining the advantages of anode electrolysis pickling speed and cathodic electrolysis pickling effect, which is carried out by alternating current or alternating pulse. However, the current acid pickling power supply is deficient in output mode, control precision, response speed and so on, resulting in a lack of research on the process and control of electrolytic pickling. Therefore, it is of great significance to develop a high precision variable polarity pulse pickling power supply, and to study the AC pulse pickling technology and control in order to improve the pickling effect. Firstly, according to the general scheme of variable polarity pulse pickling power supply, the main circuit and control system are designed. After installation and debugging, the variable polarity pulse power supply has four current output modes: DC, DC, AC symmetry and AC asymmetry, and has higher control precision and faster response speed. Can meet the needs of various electrolytic pickling process, compared with the current pickling power has a greater advantage. The process of electrolytic pickling was studied. The experimental platform of electrolytic pickling was built and the effect of current density and pulse frequency on the actual pickling effect under the condition of AC symmetric pulse current waveform was studied by single variable control method. By testing and analyzing the electric characteristic curve and observing the micro-morphology of pickling surface, it is found that the higher the current density is, the higher the pickling efficiency is when the pulse frequency is fixed, but the higher the current is, the more corrosion occurs on the surface of the sample due to the over-assembly of the current. When the current density is fixed, the optimum pulse frequency corresponding to the current density can be obtained, and the faster treatment speed and better surface quality can be obtained under the optimum frequency. The relationship between the optimum frequency and the current density of a symmetric AC pulse is obtained by multiple experiments. The mechanism and control strategy of AC pulse acid pickling for removing oxidation layer were explored. The electrochemical reaction and the change process of the surface state of the sample under the action of cathode and anode electrolysis are analyzed. The reasons for the faster treatment speed and better surface treatment quality under the optimum frequency are explained theoretically. The control strategy of AC pulse pickling is studied, and the idea of real time control and improvement of pickling process is put forward.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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