Due to the low density, high specific strength, good corrosion resistance, and excellent high and low-temperature performance of titanium and titanium alloys, they are widely used in aerospace, weapons, nuclear energy, petroleum, chemical industry, metallurgy, machinery, ships, marine development, seawater desalination, medical care, sports and leisure and other industries. With the increasing application of titanium and titanium alloys, the demand for titanium and titanium alloy materials is not limited to conventional materials such as titanium tubes, Grade 5 titanium bars, and titanium plates. Titanium sheets, titanium strips, profiles, large rings, large-diameter cylindrical parts, and various standard parts have put forward higher requirements for titanium and titanium alloy processing.
Titanium forging large-diameter cylindrical parts is a type of titanium alloy product with a large demand in recent years. In the past, the methods commonly used for large-diameter cylindrical parts of titanium forgings were: one is ingot casting → forging billet → punching → hole expansion → forging and drawing → turning; the other is ingot casting → forging → drilling and milling → turning. The first process method is used to produce large-sized thin-walled cylindrical parts of titanium forgings. Due to the temperature drop during the forging process, the deformation resistance of the titanium alloy increases sharply and deformation becomes difficult. The two end faces of the cylindrical parts often crack, and cracks also occur on the inner and outer surfaces, resulting in large material input and low yield. The second process method is used to produce large-sized thin-walled cylindrical parts. The casting structure cannot be completely broken, and the performance cannot meet the use requirements; and because the drilling and milling machine processing method is used, the processing cost is high and the production efficiency is low.
The improved process is as follows:
Ingot – Ingot – Bar – Billet – Punching – Ring – Drawing Forging – Ring
Because the target user does not have very high requirements for the final organization and performance, the requirements for its microstructure are: it must be the organization produced by two-phase processing, and there must be no complete original β grain boundary. As long as the fire deformation amount of more than 60% is used when the ingot is opened, the intermediate fire deformation amount is controlled at more than 30%, and the forging ratio of the finished tube fire deformation amount is controlled at about 1.3 as much as possible, it is guaranteed to obtain products that meet the technical requirements of users. Within the forging temperature range, the deformation resistance of Grade 5 titanium forgings increases sharply with the decrease in deformation temperature. Based on this, a steel jacket with a certain thickness is used to reduce the heat exchange with the outside as much as possible, play a certain role in heat preservation, and enable it to use a smaller forging force to complete the deformation of the metal within the forging temperature range. At the same time, it can greatly improve the plasticity of the metal and reduce or eliminate cracks caused by the sharp increase in deformation resistance due to the rapid decrease in temperature.