The Relationship Model Between Dimension And Temperature Of Hot Larger Forgings

Large forgings are the key component in the modern industry, and manufacturing techniques of large forgings is the important symbols of the productive forces in a country. Manufacturing techniques of large forgings is complex at the high operating temperatures. This process consumes material, energy and the cost. So guarantee the forging quality and improving forging technique are important for improving the productive forces and national economic benefits. The important theory basis of forging technique is from the parameters in forging process. These parameters are dimension, temperature, the ratio and the reduction. During the forging process, the dimension and temperature are real-time obtained. Meanwhile, mastering the relation between the dimension and temperature can adjust the forging process in a timely and effective manner, and the effective manner can improve the internal quality and forging precision. The relationship provides a reliable theoretical basis for the implementation of the forging process. Therefore, based on the real-time forgings information of the dimension and temperature, the relationship model of dimension and temperature is established in the forging process.First of all, based on the heat transfer theory and the heat source theory, temperature field influenced by the dimensional change in hot forging forming are analyzed, and the temperature field is showned in temperature-drop process and temperature- rise process. Combining the real-time measured the dimension and temperature, the heat transfer coefficient influenced by the dimensional change is improved, and the temperature field function in the temperature-drop process is obtained by the two-dimensional transient heat transfer. The relational function between the plastic work and heat energy is established based on the principles of energy conversion. The temperature field function in the process of temperature rise will be established by combining the moving heat source of heat conduction equation. Finally, by the superposition of temperature field function in the temperature-drop and temperature-rise process, the temperature model influenced by the dimension change is established.Secondly, combining the process of internal forming quality and the characteristic ofthe stress, the relationship between the stress and the dimensional change is analyzed. And using the differential calculus of the pluralistic function, the relational function between the dimensional change and stress is established. By the energy function and the forging large deformation formula, the deformation parameters of energy function are solved. The relational expression between the stress and temperature is obtained. Using the stress as the intermediary variables, the dimensional change model influenced by the temperature is established in the forging process.Finally, on the basis of the above model, using the measured information in the laboratory and actual forging scene, the experiment is established. The process of forming can be simulated by Deform-3d software. The feasibility of the model is validated through the simulation and experimental results, and The models guarantee the implementation of the forging process and provide a reliable theory basis.