自然环境腐蚀监测领域电阻探针的设计与应用

发布时间：2018-08-29 12:20

【摘要】：本次实验通过对电阻探针腐蚀监测技术基本原理的研究,重点了解了电阻探针感应器在腐蚀监测过程中的重要性,通过对探针结构的深入学习,在参考前人工作以及市场现有电阻探针产品形式的基础上,设计了一款用于自然环境腐蚀监测领域的电阻探针。探针设计主要从几何结构和测量接线结构两方面做技术改进。电阻探针是通过测量金属随着腐蚀的进行而引起的阻值变化来进行腐蚀监测的。探针的起始电阻越大,对探针测量电路的测量精度要求越低,同时,探针阻值占电阻探针腐蚀监测系统整体电阻的比例越大,因此腐蚀监测系统电路部分电阻的对测量结果的影响越小。因此,探针在设计时,选取了较大的起始电阻。为了获得较大的起始电阻,探针的金属部分需要选取通电横截面较小的结构,即需要获得较小的探针金属厚度。而在管状、丝状、片状等形式结构中,超薄的片状或膜状金属最易加工成型,因此探针最终选取了片状的金属结构。在探针设计阶段,共设计了三种结构的片状电阻探针。在对比分析了常见的几种微电阻测量方法后,探针电阻测量方式最终被确定为测量原理简单、测量精度相对较高的恒流测压法。探针的接线结构设计遵循的原则是降低接线电阻、提高探针电阻测量精度。探针最终设计了五个接线口,可在探针金属背面引出五条接线,与电阻探针数据采集器接口相连接。探针金属片部分主要选用了工业常用的、具有典型代表性的Q235钢制作。对比实验用腐蚀挂片采用与探针取自同一母材的金属材料制作。探针基板选用了耐腐蚀、力学性能良好的亚克力板,封装材料选用了适用温度范围较大的环氧树脂密封。探针接线用电阻率较小的铜丝,用锡铅钎料,利用电烙铁焊接成型。在实验室内进行了为期三个月的挂片失重法和电阻探针法腐蚀监测对比实验。探针金属和腐蚀挂片在定期腐蚀后进行了腐蚀产物形貌分析。探针所得监测结果与挂片法所得数据结果进行了对比分析,探针所得腐蚀速率变化趋势与腐蚀挂片法所得数据变化趋势相同,探针所得腐蚀速率整体数值比挂片法所得数值偏大,二者比值约为1.95~2.99倍。与市场同类电阻探针测试数据相比,本实验中设计制作的电阻探针测试数据准确率有明显的提高,使其具有更好的应用价值。
[Abstract]:Through the study of the basic principle of resistance probe corrosion monitoring technology, the importance of resistance probe inductor in the corrosion monitoring process is studied in this experiment, and the probe structure is deeply studied. On the basis of reference to the previous work and the existing product form of resistance probe in the market, a kind of resistance probe used in the field of corrosion monitoring of natural environment is designed. The probe design is mainly improved from two aspects: geometric structure and measuring wiring structure. Resistance probes are used to monitor corrosion by measuring the resistance changes caused by the corrosion of metals. The greater the initial resistance of the probe is, the lower the accuracy of the probe measurement circuit is. At the same time, the ratio of the probe resistance to the overall resistance of the resistance corrosion monitoring system is larger. Therefore, the effect of the partial resistance of the corrosion monitoring system circuit on the measurement results is smaller. Therefore, when the probe is designed, a large initial resistance is selected. In order to obtain a large initial resistance, the metal part of the probe needs to select a structure with a smaller current cross section, that is, a smaller metal thickness of the probe is needed. Among the tubular, filamentous and lamellar structures, ultra-thin sheet or filamentous metals are the most easily machined, so the probe finally selects the sheet metal structure. In the phase of probe design, three kinds of lamellar resistance probes were designed. After comparing and analyzing several common micro resistance measurement methods, the probe resistance measurement method is determined to be a constant current pressure measuring method with simple measuring principle and relatively high measuring precision. The principle of the design of the probe's wiring structure is to reduce the wiring resistance and improve the measuring accuracy of the probe's resistance. Finally, five connectors are designed, which can draw out five wires on the back of the probe metal and connect with the interface of the resistive probe data collector. In the part of probe metal sheet, the typical Q235 steel which is commonly used in industry is selected. The corrosion hanging plate was made from the same metal material as the probe. The probe substrate was made of acrylic plate with good mechanical properties and epoxy resin seal with a wide range of suitable temperature. The probe is soldered by soldering with tin-lead solder with copper wire with low resistivity. A three-month comparative experiment was carried out in the laboratory for the corrosion monitoring of hanging plate weightlessness method and resistance probe method. The morphology of the corrosion products was analyzed after regular corrosion of the probe metal and the corrosion hangers. The results of probe monitoring were compared with the data obtained by hanging plate method. The change trend of corrosion rate of probe was the same as that of hanging plate method. The total corrosion rate obtained by the probe is larger than that by the hanging plate method, and the ratio of the two is about 1.95 ~ 2.99 times. Compared with the test data of the same kind of resistance probe in the market, the accuracy of the test data of the resistance probe designed in this experiment is obviously improved, which makes it have better application value.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG172;O657.1

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