In the titanium alloy forging process, the original structure characteristics of the billet, including its chemical composition, impurity distribution, the selection of hot working process parameters, and the subsequent heat treatment process, will have a profound impact on the structure and mechanical properties of the final forging.
First of all, when it comes to the selection of rolling temperature, this is a crucial link. When the rolling temperature specification is properly selected and can ensure that the billet obtains a large deformation rate during the titanium alloy forging process, the adverse effects of the original structure can be effectively eliminated. However, in the actual industrial production environment, it is not easy to achieve such a high deformation rate. As the deformation rate decreases, the adverse effects of the original structure gradually become prominent, which poses a potential threat to the quality of forgings.
Taking titanium and titanium alloy ingots as an example, their original structure often presents coarse grains and low process plasticity. In order to improve this situation, the heating process before forging is particularly important. The strategy of heating the ingot above the phase transformation point and completing the main deformation process in the β zone has been proven to be effective. In the β zone, the deformation resistance of the material is significantly reduced, and the plasticity is greatly improved, which enables the cast structure to be more fully broken, thereby improving production efficiency and reducing energy consumption.
Further research and practice have shown that when the total deformation of the ingot reaches 70%~80%, the internal structure of the forging will change significantly. The originally coarse grains are refined to form a uniform and fine fiber structure. This change in the structure not only improves the tensile strength of the material but also significantly improves its plasticity index, making the forging more tough and durable when subjected to external forces.
In addition, the selection of rolling temperature also needs to consider the specific composition and impurity conditions of the material. Different titanium alloy compositions and impurity contents have different effects on the selection of rolling temperature and the evolution of the structure during forging. Therefore, in actual operation, it is necessary to formulate reasonable rolling temperature specifications and titanium alloy forging process parameters according to the specific titanium alloy materials to ensure that the quality and performance of the forgings are optimal.
In summary, the rolling temperature has a profound effect on the structure and performance of titanium forgings. During the titanium alloy forging process, the rolling temperature needs to be strictly controlled and the original structure of the billet needs to be optimized to ensure that the quality of the forging reaches the best level. At the same time, it is also necessary to formulate reasonable forging process parameters and heat treatment processes according to the specific titanium alloy materials to further improve the mechanical properties and service life of the forgings.
