The forging production process of industrial titanium ring forgings is as follows: unloading - upsetting, punching - reaming, flattening height - rough turning - rolling the ring out of the finished product - post-forging heat treatment. The main difficulties in the production are as follows: Titanium ring surface is easy to produce cracks. Titanium has a strong affinity with oxygen at high temperature, and oxygen forms a hard and brittle layer inside the substrate through continuous diffusion to the titanium substrate. Titanium forming requires multi-fire heating, grain size is easy to coarse. From the titanium ingot open billet to roll out the finished product, need multiple deformation, it is difficult to control the forging grain size and performance requirements. Large thin-walled titanium ring is easy to produce rolling defects. The forging wall thickness is thin, the height is large, easy to cause rolling ring size instability.
Industrial pure titanium is a hard-to-forge material, which is very easy to produce cracks in the forging process, and strong oxidation, once the cracks can only be cooled to room temperature and then ground to remove the cracks. In order to meet the requirements of the geometry and surface quality of the finished titanium ring, the ring billet is rough machined, cleaned of surface defects, and in special cases, chamfered and beveled.
After roughing, the surface layer of the titanium ring billet is coated with anti-oxidation paint and heated. Rolling process is a continuous line contact process, forming speed, deformation energy will make the titanium ring forging temperature rise. Therefore, to ensure that the titanium is not rolled in the β-phase zone, the heating temperature should be lower than the phase change temperature.
Titanium ring forgings in the rolling process, the speed is larger, can refine the grain, but also generate a lot of deformation heat, making the billet temperature rise, increasing the possibility of dynamic recrystallization behavior. If the ring temperature is too high, it is easy to coarse crystallization, and if it is too low, it is easy to produce cracks.
