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腐蚀及危害现象腐蚀是天然气净化厂的大敌。天然气净化厂的设备、容器、管道、阀件等钢材受到的腐蚀现象主要表现为电化学腐蚀、硫化物应力腐蚀开裂、氢脆、碱脆、疲劳腐蚀和高温硫的化学腐蚀等形式。H_2S、CO_2、SO_2、胺液、硫蒸汽等酸、碱介质是重要的腐蚀因素。此外,钢材本身的不均匀性、杂质含量程度、金相组织的不同、设备制造时的缺陷,均能加剧腐蚀产生与发展。特别是H_2S和水共存的条件下,腐蚀生成不同类型的腐蚀产物。一般钢材为阳极、腐蚀产物为阴极。但某些腐蚀产物如Fe_9S_8,由于其晶格不完整,不能阻止铁阳离子的扩散,使铁的腐蚀很快,厚度减薄、强度降低,从而形成穿、漏、裂等破坏。在水气交界部分,还会造成危害性极大的坑槽腐蚀。在天然气净化厂设备外表面,若没有完好的防腐措施,空气中的氧气与工厂中的H_2S、CO_2、SO_2等酸性气体的共同作用,使钢材受到剥层似的严重电化学腐蚀,与常说
Corrosion and damage Corrosion is the enemy of natural gas purification plant. Natural gas purification plant equipment, containers, pipes, valves and other steel corrosion suffered mainly by electrochemical corrosion, sulfide stress corrosion cracking, hydrogen embrittlement, alkaline brittle, fatigue and high temperature sulfur chemical corrosion and other forms. H 2 S, CO 2, SO 2, amine solution, sulfur vapor and other acid and alkali media are important corrosion factors. In addition, the non-uniformity of steel itself, the degree of impurity content, the different microstructure, equipment manufacturing defects, can exacerbate the emergence and development of corrosion. In particular, H2S and water coexist conditions, the corrosion of different types of corrosion products. General steel anode, corrosion products for the cathode. However, some corrosion products, such as Fe_9S_8, can not prevent the diffusion of iron cations due to the incomplete lattice. The corrosion of Fe_9S_8 is rapid, the thickness is thinner and the strength is lower. In the water vapor part of the junction, but also cause great harm to the pit corrosion. In the natural gas purification plant equipment, the external surface, without good anti-corrosion measures, the oxygen in the air and the factory H_2S, CO_2, SO_2 and other acidic gases together, so that the steel was stripped of serious electrochemical corrosion, and often say