典型材料在增产丙烯助剂生产中的腐蚀行为研究

Study on Corrosion Behavior of Typical Steels in Production of propylene producing additive

在催化裂化催化剂一些助剂的生产中,由于其特殊的生产工艺会导致设备的腐蚀加剧,为分析原因,指导设备选材,针对增产丙烯助剂生产中的腐蚀问题,采用失重法和电化学法对碳钢、304,316L,2205,Ti等五种典型金属材料在生产中涉及到的工业磷酸、工业盐酸、磷铝胶体、反应后物料四种环境下的腐蚀行为进行了研究。研究结果表明碳钢在四种介质中的腐蚀速率全部最高;奥氏体不锈钢304和316L能够耐受工业磷酸、磷铝胶体和反应后物料的腐蚀,但是相比2205和Ti点蚀敏感性高,尤其是304;Ti不适用于工业盐酸和工业磷酸这类非氧化性强酸环境,在磷铝胶体和反应后物料中则具有很好的耐蚀性,同时耐点蚀性能最优;2205除了不能耐受工业盐酸腐蚀外,在其他几种介质中腐蚀速率最低,综合性能最优。根据以上结论对现场设备材质进行了改造,实现了装置连续生产,取得了较好的经济效益。

In the production of additives for FCC catalysts, some special production processes will aggregate the corrosion of equipment. To select a good equipment material and solve the corrosion problems in the production of propylene enhancement additive, the weight - loss and electric - chemical methods were applied to study the corrosion behaviors of five typical steels like carbon steel, 304, 316L, 2205 and Ti steels in the four environments of industry phosphoric acid, hydrochloric acid, phosphorus aluminum colloid and normal effluent after reaction. The results show that the corrosion rate of carbon steel in all four media is the highest; 304 and 316 L austenitic stainless steels are resistant to the corrosion of industrial phosphoric acid, phosphorus aluminum colloid and effluent after reaction, but the sensitivity to pitting corrosion is high as compared to those of 2205 and Ti, especially 304 steel; Ti is not applicable to non -oxidizing acid environment such as industrial hydrochloric acid and phosphoric acid. , but it exhibits excellent corrosion resistance in phosphorus aluminum colloid and effluent after reaction and offers the best pitting corrosion resistance performance. The corrosion rate of 2205 is lowest in several media besides industrial hydrochloric acid, and 2205 steel has the lowest corrosion rate in the corrosive media except the industrial hydrochloric acid. The materials of field equipment have been modified based upon above analysis. The continuous operation of the unit has been ensured and good economic benefits have been achieved.