活化极化控制下合金表观与真实腐蚀极化图

提出了描述合金的腐蚀动力学存在两种腐蚀极化图:(1)合金的表观腐蚀极化图——以电极电位相对单位合金面积上的阳极电流和阴极电流为坐标系;(2)合金的真实腐蚀极化图——以电极电位相对合金中各相的真实阳极电流密度和阴极电流密度为坐标系.研究了在活化极化控制下,阴阳极面积比对合金腐蚀动力学的影响,获得了在两种坐标系中合金腐蚀动力学的定量关系式,由此建立了表观腐蚀极化图与真实腐蚀极化图之间的关系.将表观和真实腐蚀极化图两者结合起来,既可以直观地表示出合金的腐蚀速率,又可以清楚地分析控制腐蚀电池过程的机理.

Apparent and true corrosion polarization diagrams of alloys under activation polarization control

Two kinds of corrosion polarization diagrams were used to describe the corrosion kinetics of alloys. They have different coordinate systems. One is the coordinate system where the coordinates are the potential and the current on the unit area of alloy surface, the other is the coordinate system where the coordinates are the potential and the true anodic and cathodic current density. The former is called the apparent corrosion polarization diagram of alloys, and the latter is called the true corrosion polarization diagram of alloys. The effect of cathode-to-anode area ratio on the corrosion kinetics of an alloy was studied under activation polarization control. Combining the apparent with true polarization diagram, not only the corrosion rate of the alloy can be expressed directly, but also the mechanism of the corrosion cell can be analyzed clearly.