As-cast 2.25 Cr1mo0. 25 V Outline Research Of The Microstructure Evolution During Hot Deformation

The world oil industry is developing toward the direction of automation and large-scale.The size of oil industry equipment is growing, and the work environment has becomeincreasingly harsh. As the core equipment of the oil refining industry, the quality of thehydrogenation reactor directly determines the development of the oil refining industry, and itcan affect the economic development too. As it is better at resisting to hydrogen corrosion,anti-high temperature creep and high strength characteristics,2.25Cr-1Mo-0.25Vsteel isviewed as the priority material of hydrogenation reactor. However, the basic research for the2.25Cr-1Mo-0.25V steel get behind developed countries, so the performance of using isseriously affected. Therefore, in order to provide a numerical basis to the numericalsimulation and optimization process, the single-pass and double-pass methods are applied inGleeble-1500D thermal simulation machine to study high temperature deformation behaviorand softening behavior and organizational change in thermal compression process of cast2.25Cr-1Mo-0.25V steel and the grain growth process of the forging state steel is studied. Theconclusions as the follows：(1) In single pass compression tests, the stress-strain curve in the hot deformation processhas been analyzed; the deformation activation energy has been determined; the constitutiveequation has been established and the microstructure evolution has been studied by two aspectof mixed crystal and grain refined.（2）The softening behavior of cast2.25Cr-1Mo-0.25V steel in the hot compressionprocess has been studied in double-pass experiment. The result shows that the stress-straincurve of static recrystallization and Meta-dynamic recrystallization has existed; therecrystallization fraction and the activation energy have been calculated. The dynamicsequation has been created；the microstructure evolution has been analyzed by two aspect ofmixed crystal and grain refined.(3) The experiment of grain growth has been done with cast2.25Cr-1Mo-0.25V steelwhich is processed by forging ratio1.5. The grain growth in different conditions has beenstudied and the grain growth models are established.