Abstract: The corrosion process of three kinds of tubing steels in the environment of carbon dioxide was simulated with high-temperature and high-pressure autoclave.The effects of temperature on the scale thickness of corrosion product and crystal average grain size of the corrosion products were analyzed using the scanning electron microscope.The analysis results show that the scales of corrosion products from the three kinds of steels have double-layer structures in the cross sections.The maximum variation of average thickness of the scales for the three kinds of steels appeared at 120℃.However,the minimum variation of the average thickness of scales for the steels of N80 and J55 appeared at 160℃,for steel P110 at 180℃.The variations of the average grain sized of scales with temperature for the three steels exhibited a peak and a valley,respectivelyl.The temperatures corresponding to the peaks of three steels were all at 120℃,and the temperature of valleys for N80 and J55 were at 160℃ and for P110 at 180℃.The crystal grain sizes for different materials varied,but the temperature corresponding to the peak or valley of the average thickness of scales was the same with that corresponding to peak or valley of crystal grain size for every kind of steel.

Key words: corrosion product scale, carbon dioxide corrosion, temperature, scale thickness, grain size, morphology, high-temperature high pressure autoclave, scanning electron microscope

摘要： 在高温高压静态釜中对3种油、套管钢材N80、P110和J进行了CO₂腐蚀模拟试验.用扫描电子显微镜(SEM)对比分析了腐蚀产物膜的厚度和表面平均晶粒大小随着温度改变的规律.结果显示,3种材料所得到的腐蚀产物膜的纵向形貌为双层结构;其膜厚随着温度变化的最大值均在120℃处,N80和J两种钢的最小值在160℃处,而P110钢则在180℃处.3种材料成膜晶粒的尺度随着温度的变化都出现了一个峰值和一个低谷,峰值都在120℃,低谷所对应的温度却不相同.N80和J两种钢在160℃,而P110则在180℃处.虽然3种材料腐蚀产物膜的峰值或低谷存在明显差异,但每种材料膜厚的峰值或低谷所处的温度与晶粒大小的峰值或低谷所处的温度却是相同的.

关键词: 腐蚀产物膜, 二氧化碳腐蚀, 温度, 膜厚, 晶粒, 形貌结构, 高温高压釜, 扫描电镜