【作者】 刘锐；

【导师】 万平玉；

【作者基本信息】 北京化工大学 ， 化学， 2012， 硕士

【摘要】 本论文研究一种新型的涂层-电化学联合保护体系，在该体系中，含碳纤维复合象形阳极埋设在涂层内部对涂层下的碳钢进行阴极保护，其特点是在被保护金属基体上涂覆不导电的普通防腐涂料，再覆盖由网状碳纤维和导电涂层共同组成的平行于阴极而且和阴极等面积的象形阳极。由于阳极平行于被保护金属的表面，可以得到较均匀的电力线，从而得到较均匀的保护效果。碳纤维虽然导电，但是其本身的电阻仍不可忽略，尤其对于长距离的保护来讲。因此，本文重点对碳纤维与基体金属之间的电位差沿经线方向(远离电源的方向)降低的规律进行了建模分析求解和实测检验，研究确定并量化了碳纤维经线欧姆电压降及最大电化学保护距离与碳纤维经线粗细、间隔以及底漆涂层湿电阻之间的对应关系。对已知阻值的电阻网络进行了实际电压分布的测量和数学模型的理论计算，结果表明二者所得出的电压分布曲线完全重合。证明了模型的正确性。又用一个一米长的涂层试件进行了实际阴极保护电位分布的测试，得出了实测和理论计算二者较吻合的满意结果，在该长试件的测试中，利用在一定的阳极电流范围内碳纤维阳极电位稳定的特点将电压分布曲线成功地转换为电位分布曲线，从而证明了该数学模型对保护系统工程设计的理论指导作用。采用碳纤维复合象形阳极的优点是可以用于一些分立阳极较难安装的场合，如一些介质电阻过高，远距离没有足够的空间安装阳极的场合。另一个可应用的场合就是船体的保护，因一般船体保护体系的分立阳极均突出船体表面数厘米而产生附加航行阻力，而本论文研究的碳纤维阳极就在涂层内部，而且测量电位用的参比电极也是埋设在涂层中，这样就可以大大减少航行的附加阻力。为此本论文对船体的保护进行了重点的讨论。论文还采用交流阻抗技术测试最佳保护电位，对碳纤维极化行为、埋设在涂层中的锌参比电极的安装和抗电流干扰性能以及采用恒槽压法作阴极保护控制方法的可能性等进行了详细的讨论。更多还原

【Abstract】 The present dissertation studies a new cathodic protection system, inwhich carbon fiber sparse gauze was embedded in the coating andemployed as anode. Since carbon fiber anode and the metal base cathodeare parallel and have the same area, the power lines are parallel and thus aeven protection could be achieved. Although carbon fiber is electricallyconductive, its electric resistance is still not negligible. So thisdissertation emphasizes the study of the effect of carbon fiber resistanceon the distribution of cell voltage along the direction remote from powersource. Two mathematical models of current introduction from bothsingle side and double side for the computation of cell voltagedistribution were established respectively. The relation betweenprotection distance and the parameters of section area, inter-stranddistance of carbon fiber and coating resistance is discussed. A test ofelectric resistance network of which the values of resistance were knownwere carried out and the result shows the measured and theoreticalpotential distribution curves overlap each other, validating the correctnessof the mathematic model. A long specimen test result shows a good agreement between the theoretical and measured potential distributioncurves. In this long specimen test, taking advantage of the stability of thepotential for carbon fiber anode in a certain range of anodic current, thecell voltage distribution was successfully converted into potentialdistribution on the protected metallic base, demonstrating the feasibilityand guiding role of the mathematic model.The advantage of carbon fiber gauze anode is the possibleapplication in the field where the separated anodes are difficult to installand the field where the resistance of the medium is too high and there isno enough space for anodes to install in remote places. Another field isthe ship hull protection, for which the separated anodes protrude from thehull surface about several centimeters, leading to some additional sailingresistance. But in my study, the anode and reference electrode are allembedded in the coating. So the additional sailing resistance would bedecreased considerably. In this dissertation, a detailed discussion isemphasized on ship protection.AC impedance measurement was employed to select optimalprotection potential. The polarization behavior of the carbon fiber, theinstallation of zinc reference electrode and the potential control measureare also discussed.更多还原