专业英语第三章（Special English third chapters）.doc

专业英语第三章（Special English third chapters） Three point one Hot working; physical metallurgy It is now accepted that the principles of hot working physics and metallurgy. In the deformation process itself, for example, a rolling pass, the process hardening occurs, but the dynamic softening balance of the recycling and recrystallization processes. These processes, which are thermally activated, lead to a flow stress, strain rate and temperature, as well as strain dependent. The structural change of strain with dislocation density increases with the result of placing a critical strain (epsilon C) in austenitic steel, nickel and copper alloy material, until the stored energy is high enough to cause dynamic recrystallization. With further pressure, dynamic recrystallization occurs repeatedly at the critical level of the new recrystallized grains themselves, which work to harden the stored energy. These dynamic structural changes leave the metal in an unstable state and provide the impetus for static recovery and static recrystallization after deformation transfer. The growth of crystalline grains may follow the static recrystallization if the temperature is high enough. In order to be able to put these principles into the business process, we need to answer two main questions: (a) transfer in place long after recrystallization and deformation; (b) what the recrystallized grain size and grain growth? The answers to these questions determine the structure of the material to pass into the future and the subsequent, thereby affecting the flow stress of the material and the required work force. Finally, they determine the structure and nature of the heat product Dynamic structural changes in 3.1.1 In the deformed austenite at hot working temperature and constant strain rate, the characteristic form of stress-strain curve is observed as shown. 3. 1. These curves are tested for torsion tests of low alloy steels, but similar to other steels are obtained for torsion, tension, or com