(1. 东北石油大学 机械科学与工程学院，大庆 163318；
2. 大庆油田有限责任公司 建设集团，大庆 163159；
3. 中国石油集团长城钻探工程有限公司 工程技术研究院，盘津 124010)
摘 要: 基于第一性原理计算法，采用CASTEP模块计算稀土Ce掺杂Cr13钢的吸附能，分析稀土Ce对Cr13钢耐CO2腐蚀性能的微观影响机制。通过等离子电弧炉制备添加不同含量Ce元素的Cr13钢，测试合金的显微组织及其在含饱和CO2的3.5%(质量分数)NaCl液中的腐蚀电化学行为。结果表明：Cr13钢掺杂稀土Ce后，吸附结构的稳定性减小，Ce含量为0.1%(质量分数)时，吸附结构的稳定性最小。适量稀土Ce添加可细化基体铁素体晶粒、减小碳化物的数量及偏聚。稀土Ce掺杂Cr13钢在含饱和CO2介质中呈现出明显的钝化行为，Ce的添加量与钝化稳定性间存在临界值，当稀土Ce添加量为0.1%时，钝化电流密度最小、钝化区间最宽，具有最优的抗CO2腐蚀性能。第一性原理计算方法在预见材料耐CO2腐蚀性能方面具有很强的可靠性，对设计耐蚀材料具有较强的指导意义。
关键字: 第一性原理；Cr13钢；稀土元素；抗腐蚀性能
（1. School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318, China;
2. Construction Group, Daqing Oilfield Co., Ltd, Daqing 163159, China;
3. Engineering and Technology Research Institute,
China National Petroleum Corporation Greatwall Drilling Company, Panjin 124010, China）
Abstract:The adsorption energy of Ce doped Cr13 steel was calculated by CASTEP module based on the first principle method. The effects of Ce on the CO2 corrosion resistance of Cr13 steel were analyzed. The Cr13 steel doped different Ce contents was prepared by plasma arc furnace. The microstructure and electrochemical corrosion behavior of prepared alloys in the 3.5% (mass fraction) NaCl solution saturated with CO2 were investigated. The results indicate that the stability of adsorption structure reaches to a minimum value when the content of Ce is 0.1% (mass fraction). The adsorption quantity of Ce can refine the Fe grain and reduce the amount of carbide, leading to little segregation of alloy elements. Ce doped Cr13 alloys exhibits the remarkable passivation behavior. When the content of Ce is 0.1% (mass fraction), the passivation current density is the lowest and the passivation region is the widest, and the alloy exhibits the enhanced CO2 corrosion resistance. The first principles method shows a promising application in forecasting CO2 corrosion and has much directive meaning in designing new ant-corrosion materials.
Key words: first-principles calculations; Cr13 steel; rare earth element; corrosion resistance
