中碳钢在海水中阴极保护紫铜的二维有限元法计算研究

2-DIMENSIONAL FINITE ELEMENT METHOD FOR CATHODIC PROTECTION OF COPPER BY MEDIUM CARBON STEEL IN SEAWATER

对于中碳钢在海水中作为牺牲阳极阴极保护紫铜而建立了6个二维物理模型。对Laplace方程进行了弱形式推导以便于有限元法计算。用有限元法模拟计算了各物理模型阴极保护体系的电位分布,并进行实验验证。结果表明,二维有限元法能很好地模拟该阴极保护体系的电位分布。在小范围内中碳钢和紫铜电偶对的距离远近对电位分布影响不大。各模型中具有代表性的X轴、Y轴方向的电位模拟计算值与实测值接近。中碳钢阴极保护紫铜具有可行性,有限元法计算能够为其阴极保护设计提供依据。

Six different 2-D physical models for cathodic protection of copper by medium carbon steel as sacrificial anode in seawater are built in this paper. Weak form of Laplace equation was deduced to make finite element method （FEM） numerical calculation convenient. Then, potential distribution of various physical models was computed by FEM, and followed by experimental measurements for validation. The results show clearly that potential distribution of the cathodic protection system could be well simulated by the 2-D FEM solution. The distance of the galvanic couples is not a key factor influencing potential distribution in small range. Typical simulation data （along X-axis and Y-axis） of different models are consistent with the experimentally measured results. Therefore, it should be feasible to cathodically protect copper with medium carbon steel as sacrificial anode, and FEM could afford well a basis for cathodic protection design.