| China is rich in Mo resources as the greatest country with Mo resources in the world, but not the most powerful country in research of molybdenum resource. Molybdenum products almost are primary blank. Molybdenum and its alloys with high melting point, high temperature strength, small expansion coefficient, good thermal conductivity properties, and lower creep rate at high temperature are widely used as an important national strategic materials in metallurgy, electric power equipment manufacturing, aerospace and defense industry. The molybdenum alloy doped with rare earth La2O3has excellent performance. Mo-La alloy has become the significant research focus of foreign scholars. However as Mo and Mo-La alloy has high temperature strength and low ductility, is intensive oxidation at high temperature, the rolling equipment of molybdenum and molybdenum alloy must be special and the rolled plates have many defects such as head cracking, layer, edge crack and so on, as result of low rate of passable products And the rolling Mo-La plate has much ductility and obvious anisotropy. As a result, further processing of the molybdenum and Mo-La alloy such as stamping are difficult limiting the development and application of molybdenum products This paper fund by the project of the largest molybdenum industry company in China Jinduicheng Molybdenum Group, based on research of Pure molybdenum simulation study in the early stage, the research of Mo and Mo-La alloy rolling process was finished aiming at plates with high performance and small anisotropy. The research contents of this paper are as follows:(1) With the thermal simulation experiment, single-pass compression deformation behavior of sintered Mo-La alloy at high temperature was studied and the influence of deformation parameter on resistance to deformation was analyzed Meanwhile dynamic softening behavior of pure Mo for various sintered density was also studied, and activation energy of dynamic recrystallization called Q was counted as well as the modified Arrhenius formula of Mo-La was built.(2) By rolling experiment, comparison to sintered pure molybdenum hot rolling and warm rolling process, the process of sintered molybdenum lanthanum was studied. Mo-La billet cogging temperature is about1450℃, and cogging reduction rate at30%-40%. Five passes was exactly suitable at the first time heating. the second heating temperature is about1400℃, rolling4passes, processing rate for hot rolling is generally20%-30%Mo-La alloy rolling temperature and annealing temperature are both higher than pure molybdenum.(3) The microstructure of Mo was observed under different process, and the dynamic recrystallization behavior was analyzed under the condition of high temperature deformation. Cross rolling of molybdenum and molybdenum alloys in the warm rolling stage was studied aiming at improving the molybdenum alloy plate performance with smaller anisotropy.(4) The influence of hot rolling, warm rolling and annealing on the microstructure and performance of Mo-La and Mo were analyzed and the different way of cross rolling has significant effect on improve the anisotropy.it means that the compression ratio of rolling direction (z direction) has different effect on decreasing the anisotropy.(5) On the basis of the results for rolling experiment, a bigger scale industrial pilot was finished to test the stability of hot rolling process of Mo and Mo-La alloy and calculate the rolling yield of Mo and Mo-La hot rolled plates. |
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