| Hydroprocessing reactor, which is the significant key equipment of modern petroleum refining industry, is mainly used in technical processes such as refining of fossil oil, hydrocracking, hydrofining, catalytic reforming, desulphurizing and depriving of heavy metals from heavy oil. With the developing trend of automatization and large scale of international oil industry, the dimensions of the existing hydroprocessing equipment become bigger and bigger, thus, the extensively adopted 2.25Cr-1Mo steel cannot meet the need any longer. Meanwhile, the hydroprocessing reactor made of the 2.25Cr-1Mo steel used to expose many problems, such as high-temperature temper embrittlement, hydrogen brittleness of stainless steel welds, and hydrogen-induced stripping of stainless steel claddings, etc. In recent years, many developed countries have begun to make hydroprocessing reactors with the new material-----the 2.25Cr-1Mo-0.25V steel, whose strength and malleability have been greatly improved comparing with traditional steels. Additionally, the 2.25Cr-1Mo-0.25V steel boasts the features of high-temperature temper embrittlement resistance, hydrogen embrittlement resistance, and hydrogen-induced stripping resistance of stainless steel claddings. Therefore, the research on the structure property and weldability of the 2.25Cr-1Mo-0.25V steel and the quality control during technical research of cladding 2.25Cr-1Mo-0.25V on 0Cr20Ni10Nb and project application will provide important theoretical value and practical meaning for researching and exploiting hydroprocessing reactors made of the 2.25Cr-1Mo-0.25V steel.China is just at the beginning of manufacturing hydroprocessing reactor with the 2.25Cr-1Mo-0.25V steel. And only a few companies are able to manufacture hydroprocessing reactors with it. This thesis paper aims at exploiting and researching on the techniques, particularly the key method of producing hydroprocessing reactor with the 2.25Cr-1Mo-0.25V steel, i.e. applicable theory of cladding.In accordance with the techniques of manufacturing hydroprocessing reactor, this thesis paper thoroughly probed into the physicochemical properties, influential mechanics of material mechanics properties under different heat-treatment processes, estimation data and technology of the inclination of temper and embrittlement, theoretical analysis of the weldability of 2.25Cr-1Mo-0.25V steel, welding crack test on Y-shaped samples, test of maximum hardness on welding heat-affected zone, and test of reheat-resistant cracks, respectively. Meanwhile, on the basis of relevant experiments on 60mm and 90mm electrode-banded cladding, this thesis paper made technical estimation on 2.25Cr-1Mo-0.25V steel cladding according to actual production, obtained cladding structure with uniform chemical constitution, which can meet the technical requirement, through experimental analysis and technical optimization. At the same time, the thesis paper analyzed factors resulting in cladding deficiency, established appropriate technical process of cladding, and provided technical gist for production application and quality demonstration.
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