薄层液膜下CO2腐蚀测试的实验装置开发

Development of An Experimental Device for CO2 Corrosion Testing in Thin Water Film

开发了一套可在控温、控湿环境中开展不同形态薄层液膜下CO2腐蚀测试的实验装置,以适应薄层液膜下的CO2腐蚀机制及规律研究需求。实验装置主要由环境控制系统、液膜厚度测量系统和腐蚀电化学测试系统组成。环境控制系统主体为有机玻璃做成的密闭环境腔,既可以开展控温、控湿以及承压环境下的实验测试,同时又可方便地观察腔体内情况。薄层液膜形态包括不同厚度的均一液膜和存在厚度梯度的不均一液膜,由液膜厚度测量系统获得不同液膜形态下的CO2腐蚀行为。结果表明:金属CO2腐蚀速率随液膜厚度的不同而不同,液膜厚度相同但均一性不同时,CO2腐蚀行为也存在差异。

An experimental device which enables CO2 corrosion testing in thin water film of various patterns under well controlled temperature and humidity condition was developed.This device can be used to study CO2 corrosion mechanism and behavior under specific thin water film.The device mainly contains three subsystems,including environmental condition control system,water film thickness measurement system,and electrochemical corrosion testing system.The environmental condition control system is a sealed chamber that was made of acrylic,providing well controlled temperature,humidity and pressure condition for the testing.Two patterns of water film considered includes uniform water film with various thicknesses and non-uniform water film with thickness gradient.The water film thickness measurement system was combined with the adjusting of the levelness and/or inclination angle of the working surface to control and characterize the water film pattern.The electrochemical corrosion testing system supports both the conventional three-electrode testing and the electrode array testing,thus CO2 corrosion behavior under different patterns of water film can be measured.The preliminary result show that CO2 corrosion rate is dependent on water film thickness.In addition,CO2 corrosion behavior varies for conditions with the same water film thickness but different uniformity.