The Reserch Of Thermal Stress Testing For Large Hot Sharft Forgings Based On Heat Conduction Model

Large shaft forgings are critical components in many significant national energy security. Such as mine, petrochemical industry, nuclear power industry, power plant, and so on. The quality standard of large shaft forgings is become more and more harsher with the rapid development of the construction process of industrialization. Therefore, the production ability of large shaft forgings has been one of the important symbols of nations’ technological strength and industrial economic level. In the process of large shaft forgings’ forging, the uneven temperature field of forgings can make the forgings produced thermal stress. What is important is that the forgings’ quality, plasticity, toughness, intensity and so on can be influenced directly by thermal stress. What is more, excessive thermal stress can cause forgings scrap. The thermal stress of forgings is an important factor that affects the quality of forgings. Therefore, for the accurate implementation of forging process and the quality of forgings, it has great significance to grasp the thermal stress of large hot forgings’ variation. Based on unsteady heat conduction theory and thermal elastic mechanics theory, the thermal stress of large hot shaft forgings is studied during forging. The main contents of the paper are represented as follows:Firstly, based on unsteady heat conduction theory, the heat conduction equation of large forgings is carried out. And the solution condition of forgings’ heat conduction theory is provided. Through analyzing the heat conduction variation of large hot shaft forgings, the heat conduction model of large hot shaft forgings is established. The method of variable separation is used to solve the model, the temperature field of large hot shaft forgings is obtained. The research lays a theoretical foundation for the thermal stress testing of large hot shaft forgings.Secondly, according to thermodynamics related theory in the process of forging, the thermal elastic constitutive equation of forgings is derived. On the basis of the established conduction model of large hot shaft forgings and the thermal elastic mechanics theory, the thermal stress testing model for large hot shaft forgings is established. At the same time, the thermal stress testing model for large hot shaft forgings is solved.Finally, the heat conduction model of large hot shaft forgings and the thermal stress model of large shaft forgings are established in the finite element software. And the finite element simulation of forgings is conducted. Applying MATLAB software, the analytical data of models are acquired. The simulated data of large hot shaft forgings and analytical results data of models are compared and analyzed. And the experimental results indicate that the established thermal stress testing of large hot shaft forgings is effective.