碳钢在含硫化氢及高压二氧化碳饱和的NaCl溶液中的腐蚀行为

利用自制的高温、高压腐蚀试验及电化学测试装置，通过失重法、电化学极化曲线法及电子探针微观分析等方法，研究了温度、硫化氢浓度对碳钢在高压二氧化碳饱和的39％NaCl溶液中腐蚀的影响．结果表明较低温度(80℃)下，升高温度及增大硫化氢浓度均加速腐蚀反应的阴、阳极过程，失重腐蚀速率增大；高浓度的硫化氢抑制了腐蚀反应的阴极过程；120℃时碳钢CO2腐蚀产物膜对金属基体起很好的保护作用，失重腐蚀速率减小了3～4倍，随硫化氢浓度的增大，失重腐蚀速率缓慢增长，腐蚀产物FeCO3膜逐渐转变为以硫铁化合物为主的腐蚀产物膜．

CORROSION BEHAVIOR OF CARBON STEEL IN HIGH PRESSURE CARBON DIOXIDE SATURATEDNaCl SOLUTIONS CONTAINING HYDROGEN SULFIDE

Using a self-made autoclave for corrosion testing and electrochemical measurements under highpressure conditions, the effects of temperature and hydrogen sulfide concentration on the corrosion ofcarbon steel in high pressure CC2 saturated 3 % NaCl solutions were studied by weight-lcss method,electrochemical polarization technique, electron probe microscopy analysis (EPMA). Experimental resultsshowed that temperature and hydrogen sulfide concentration had obvious effects on the corrosion rate,configuration and character of corrosion scales. The adhesivity and protectivity of corrosion scale fomned atlower temperature (80℃) were poor. The rising of temperature accelerated cathodic and anodic process ofcorrosion reaction and at the same time increased corrosion rate. Dense iron carbonate film was formed onsteel surface at 120℃, which exhibited good adhesivity and protectivity. The corrosion rate of steel at120℃ was only one fourth of that at 80℃. Electrochemical polarization indicated that at 120℃ cathodicprocess ofi corrosion reaction was accelerated, while the anodic process was restrained. At the lowertemperature(80℃ ), both cathodic and anodic process of corrosion reaction were accelerated and thecorrosion rate increased with increasing the concentration of hydrogen sulfide. The cathodic process ofcorrosion reaction is restrained at the higher concentration of hydrogen sulfide. At the higher temperature(120℃), with increasing the concentration of hydrogen sulfide the corrosion scale gradually changed fromiron carbonate film to corrosion scale mainly made up of sulfur/iron compound. Electrochemicalpolarization indicated that cathodic process of corrosion reaction was accelerated but the anodic processwas restrained.