| As the depth of oil exploration is deepened, crude oil resources develop to the direction of poor quality. The specific gravity, viscosity, the content of sulfur and heavy metal are increased, which causes serious corrosion of equipments and affectsthe safety in production of oil refining enterprise, resulting in economic losses. Some corrosive substances, such as ammonium chloride and ammonium hydrogen sulphide, are generatedduring the process of preparing sour crude oil, catalytic cracking, atmosphere-vacuum distillation and hydrofining. Due to lack of equipment material selection and operating experience and other factors, the corrosion of the hydrogenation sewage unit, non-hydrogenizationsewage unit and solvent regeneration unit of the oil refinery is increasingly prominent, which is a serious problem. Therefore, it is very significant to study the corrosion resistance of the metal material. The results can provide some references for the material selection of the refinery equipment and corrosion inhibitor added.1. The corrosion behaviors of six metal materials in six media are investigated. The corrosion rates of six metal materials (A3,304,321,316L,2520,0Cr13) in six media (hydrogenation sewage, fresh solvent, hydrogenation barren solution, hydrogenation rich solution, non-hydrogenation barren solution and non-hydrogenation rich solution) are studied by electrochemical method and corrosion weight loss test. The results show that the corrosion resistance of six metal materials in a variety of mediais as follows:2520> 304> 321> 316L>0Cr13>A3. The corrosion rate of A3,316L,321 and 0Cr13 in the hydrogenation sewageis increased linearly with the increase of temperature at 30-90?. The corrosion rate of 304 in the hydrogenation sewage is increased slowly with the increase of temperature below 50?, and increased rapidly with the increase of temperatureat 50-90?. The corrosion rate of 2520 in the hydrogenation sewage presents a cubic function tendency with the increase of temperature.2. The stress corrosion behaviors of six metal materials in the hydrogenation sewage are studied bythe tensile test. It is found that 2520 has lower stress corrosion sensitivity3. For the metal material A3 in the six media, the corrosion inhibition efficienciesof four corrosion inhibitors (inhibitor A:TH-AC10, inhibitor B:HB-AZ, inhibitor C:691-1 57C, inhibitor D:693-1 GE57C) are studied by the electrochemical method. The results show that inhibitor B or inhibitor D can be used as industrial corrosion inhibitor in the hydrogenation sewage medium. Inhibitor C or inhibitor D can be used as industrial corrosion inhibitor in the fresh solvent medium. Inhibitor C can be used as industrial corrosion inhibitor in the hydrogenation barren solution medium. Other inhibitors are suggested to be used in the hydrogenation rich solution medium. Inhibitor D can be used as industrial corrosion inhibitor in the non-hydrogenation barren solution medium. The corrosion inhibition efficiency of all the four inhibitors in the non-hydrogenation rich solution medium is poor, so other inhibitors are recommended to be used. The anticorrosion properties of 14 coatings in six media are studied by the chemical immersion method. The results show that custard chlorosulfonation, epoxy iron red, coal tar epoxy and 475? heat resistant paint are recommended to be used in the hydrogenation sewage medium. 475? heat resistant paint, red lead epoxy primer and zinc-rich epoxy are applicable in the fresh solvent.475? heat resistant paint and epoxy grey are suitable in the hydrogenation barren solution.475? heat resistant paint and zinc-rich epoxy are recommended to be applied in the hydrogenation rich solution.475? heat resistant paint, zinc-rich epoxy and epoxy grey are suitable in the non-hydrogenation barren solution.475? heat resistant paint, epoxy grey, zinc-rich epoxy and red lead epoxy primer are recommended in the non-hydrogenation rich solution. |
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