Thermal processing, mainly forging, rolling, and extrusion, is the basic means of production of semi-finished and finished titanium flanges. In view of the titanium flange organization and structure of the hot working, the process has a strong sensitivity, so the correct selection and mastery of process parameters is not only very important to ensure the accuracy of the product’s external dimensions, but also a key factor in the internal quality of the product.
Compared with the general metal structure materials, titanium flange thermal processing is characterized by large deformation resistance, and the deformation temperature range is narrow. Titanium with a hexagonal crystal structure is not easy to deform. In order to improve the plasticity, it is necessary to heat the metal to the b-phase region above the phase change point for the so-called b-processing. However, due to the titanium flange overheating tendency, high-temperature heating will cause b grain to grow sharply, but if the deformation amount is insufficient, after cooling the formation of coarse Wei's organization will significantly reduce the alloy’s period of time and fatigue strength, and month this overheating organization in the subsequent heat treatment in the difficult to eliminate, so the current production of finished products or finished products before the first fire of the starting temperature of the heat processing regulations do not have to go over the critical point of Tb. Due to the titanium flange’s resistance to deformation, the deformation resistance of titanium flange deformation temperature reduction or deformation rate increase is very sensitive, so the stop-forging temperature can not be too low. The constraints of these two factors, so that most of the finished titanium flange processing temperature range is limited to 800 a 950 ℃ between the mastery is not easy. But for the ingot of the open billet, the temperature range can be expanded to 850 and 1150 ℃, in the subsequent fire times in the processing process, and then the temperature step by step.
Titanium flange alloy thermal conductivity is poor, in the rapid deformation, the heart of the workpiece warms fast, due to the slow transfer of heat and easily causes overheating, while the surface temperature of the workpiece is low and easily forms surface cracks, so the processing process needs to pay attention to master the deformation rate and deformation.
