备用天然气钢管盐雾腐蚀实验研究  

Study on Salt Spray Corrosion of Spare Natural Gas Steel Tube

作　　者：王卫 李欣 李进[2] Wang Wei Li Xin Li Jin(CNOOC Gas Pipelining Limited, Haikou 570105 School of Materials and Chemical Engineering, Hainan University, Haikou 570228, China)

机构地区：[1]中海石油管道输气有限公司,海南海口570105 [2]海南大学材料与化工学院,海南海口570228

出　　处：《广东化工》2017年第19期30-33,共4页Guangdong Chemical Industry

摘　　要：采用钢管切片进行盐雾腐蚀实验,设置不同的盐雾腐蚀试验周期,将所得的腐蚀钢片进行质量损失测试、SEM表征、拉曼光谱表征、EDS分析和力学性能测试,并分析其腐蚀机理。结果表明,在盐雾腐蚀初期α-FeOOH含量较高,γ-FeOOH和γ-Fe_2O_3含量次之,α-Fe_2O_3的含量最少。而随着盐雾腐蚀时间的延长α-FeOOH的含量快速下降,γ-FeOOH和-Fe_2O_3的含量较大,同时也含有一定量的α-Fe_2O_3和Fe_3O_4。随着盐雾腐蚀时间增加,质量损失随之增加,钢片表面腐蚀深度增加。拉伸性能随腐蚀时间增加呈现先减小后变缓再减小的趋势,屈服强度和断后伸长率则呈现先缓慢降低再明显下降的趋势。管线钢的点蚀主要是又Cl-引起,盐雾腐蚀的过程包括点蚀诱发和点蚀扩展。In the experiment of steel slice corroded by salt spray, testing cycle was set as the only variable, then obtained corroded steel slices were evaluated by quality loss; characterized by SEM, Raman spectrum; analyzed by EDS; its mechanical property was tested and finally analyzed its corrosion mechanism. The results showed that at the initial stage of salt fog corrosion, the content of α-FeOOH was relative high, the content of γ-FeOOH and γ-Fe2O3 were followed, and ct-Fe2O3 was the least. However, the content of α-FeOOH decreased rapidly with the prolonging of salt fog corrosion time, and the contents of the γ-FeOOH and γ-Fe2O3 was relative high, and there was also a certain amount of α-Fe2O3 and Fe3O4. With the increasing time of salt fog corrosion, the quality loss increases, and the corrosion depth of steel sheet increases. Tensile property shows a trend of first decreased and then slowly decreased with the time of corroded, yield strength and percentage elongation alter fracture show a trend of first decreased and then obvious downward trend. Pitting corrosion of pipeline steel is mainly caused by Cl-. The process of salt spray corrosion includes pitting initiation and pitting propagation.

关 键 词：盐雾腐蚀 备用钢管 点蚀 

分 类 号：TE642[石油与天然气工程—油气加工工程]