【作者】 韩烨；

【导师】 崔振铎；

【作者基本信息】 天津大学 ， 材料学， 2012， 博士

【摘要】 硫腐蚀是石油化学工业中常见的现象,对生产和安全都会造成不良的影响。中国石化公司胜利油田东营压气站的压缩机系统由于遭受硫腐蚀,离心机内部轴套出现了严重的磨损现象,成为安全生产的隐患。针对此情况,我们提出本课题来研究并解决硫腐蚀带来的设备磨损问题。运用EDS、AAS、IR等手段,对压缩机系统各部分采集的样品进行成分分析。结果表明,压缩机内部的腐蚀磨损问题,是由硫的化学腐蚀和电化学腐蚀共同造成的。根据现场情况,将研发新型缓蚀剂作为后续研究工作的主要内容。添加缓蚀剂以其成本低廉、操作简便,效果明显等优点,成为石油天然气生产中控制腐蚀的有效手段。在实验室的研发工作中,一种新型缓蚀剂TD-02得以成功制备。利用失重法、SEM和电化学测量手段对其缓蚀性质进行研究。结果表明,缓蚀剂TD-02的添加有效地抑制了腐蚀的过程,实验室缓蚀剂效率超过90%。缓蚀剂分子由于吸附作用在金属基体的表面生成了一层保护膜,并通过几何覆盖效应发挥缓蚀作用。一系列现场实验的结果表明,缓蚀剂TD-02的添加产生了明显的效果。在缓蚀剂添加实验结束后,试样表面呈光亮的黑色,其表面形貌与腐蚀前十分接近。EDS分析的结果显示S元素的含量已经可以忽略不计,且试样失重也不明显。缓蚀剂的实用试验表明,磨损情况得到有效的抑制,达到了预期的效果。通过电化学测试手段研究了正丁胺作为缓蚀剂在3%NaCl中的极化行为,实验中发现了正丁胺的诱导钝化现象。诱导钝化作用的造成是由于阴阳极电流密度对缓蚀剂分子覆盖率微分值的不同,并非是电化学动力学机构的改变。提出了一种数值分析方法并以此研究碳钢在亚硝酸钠溶液中的钝化动力学规律。通过分析得到了钝化膜覆盖率-时间曲线并进行了讨论。在极化达到致钝电位时,膜覆盖率增长速率达到最大,并且得到此时钝化膜覆盖率为77%,这说明钝化膜在此之前就已经开始形成了。更多还原

【Abstract】 Sulfur corrosion is a common phenomenon in petrochemical industry which has negative impact on production and safety. The wear of the compressor shaft caused by the sulfur corrosion poses a serious threat to product safety in Dongying compression station. A special issue of corrosion prevention and controlling was raised to deal with the problem.Site investigation has been carried out, which including the composition analysis of samples collected in several parts of the oil gas compressor system. Samples were analyzed with EDS, AAS, IR,etc. The results indicated that the wear of the compressor was caused by the chemical and also electrochemical corrosion of sulfur. Developing a new kind of corrosion inhibitor has been performed to deal with the wear in the next work.Inhibitors are frequently used for controlling sulfur corrosion in oil and gas production due to its low cost, easy operation and significant effects. In the Lab. work, a corrosion inhibitor TD-02 was prepared, and the inhibition properties of TD-02 were investigated by weight loss, SEM and electrochemistry measurements in saturated hydrogen sulfide solution. The results show that significant inhibition effect was achieved by adding TD-02 as inhibitor, which has a high inhibitive efficient more than 90% in lab experiment. A protective film is formed by adsorption of inhibitor molecules on the matrix and inhibition achieved by geometry covering.A series of field tests were carried out in Dongying compression station. The results show that significant inhibition effect was achieved by adding TD-02 as inhibitor. The sample surface was shiny black after field test, and the morphology is very close to the situation before the test. The EDS results show that the content of S can be ignored basically and the loss weight results are not obvious also. The field test results indicated that the wear of the compressor shaft was significantly inhibited, which achieves the desired results.An inducement passivation effect of normal-butylamine (nBA) was discovered in our work. The effect of inhibitor present during potentiodynamic scanning in 3%NaCl solution was investigated by electrochemistry measurement methods. The inducement of passivation is caused by the difference between the differential coefficient of anodic and cathodic currents to inhibitor coverage ratio.A numerical analysis method is proposed and applied to study passivation kinetics of low carbon steel in sodium nitrate solution. Curve of passive film coverage against time is obtained and discussed. A maximum growth rate is found at initiating passive potential during the film forming process. A 77% film coverage ratio is obtained at the initiating passive potential, which indicated that the film has already begun forming before the initiating passive potential arrived.更多还原