Thermal processing, mainly forging, rolling and extrusion, is the basic production method for titanium flange semi-finished products and products. In view of the sensitivity of the titanium flange structure to the rooting of the hot working process, the correct selection and mastery of the process parameters is not only important for ensuring the dimensional accuracy of the product, but also the intrinsic quality of the product.
Compared with general metal structural materials, the thermal processing characteristics of titanium flanges are characterized by large deformation resistance and narrow deformation temperature range. The hexagonal crystal structure of titanium is not easily deformed. In order to improve the plasticity, it is necessary to heat the metal to the b-phase region above the transformation point to perform the so-called b-processing. However, due to the high tendency of titanium flange to overheat, high temperature heating will cause b crystal grains to grow sharply. However, if the deformation amount is insufficient, the formation of coarse Wei’s structure after cooling will significantly reduce the alloy’s properties and fatigue strength. The organization is difficult to eliminate in the subsequent heat treatment, so the current hot working starting temperature for the finished product or the finished product in the current production does not require a critical point Tb.
Since the deformation resistance of the titanium flange is very sensitive to the reduction of the deformation temperature or the deformation rate, the stop forging temperature cannot be too low. The constraint of these two factors makes the processing temperature range of most titanium flanges limited to 800-950 °C, which is not easy to master. However, for the blanking of the ingot, the temperature range can be expanded to 850 to 1150 ° C, and the temperature is successively lowered during the subsequent processing of the fire.
Titanium flange alloy has poor thermal conductivity. In the case of rapid deformation, the temperature rise of the workpiece core is fast, the heat transfer is slow and it is easy to cause overheating, while the surface temperature of the workpiece is low, and surface cracks are easy to form. Therefore, it is necessary to pay attention to the deformation during the processing. Rate and amount of deformation.