TC4(GR5) titanium alloy is one of the most widely used titanium alloys at present. It has high strength and good corrosion resistance. However, it is difficult to manufacture and supply TC4(GR5) seamless titanium tubes in domestic and foreign markets.　

TC4(GR5) titanium is mainly made of plates, while the market TC4(GR5) titanium tubes are mainly made of high-strength thick-walled tubes produced by hot extrusion or oblique perforation, etc. This warm rolling process requires the improvement of traditional rollers, namely the installation of induction heating device on the pipe rolling machine. Such processing equipment is complicated in structure, manufacturing process and cost highly in production. The main reason for the current situation is the high strength of TC4(GR5) titanium alloy and the difficulty of cold rolling forming. In order to solve the key technology of TC4(GR5) seamless tube cold rolling forming, a series of studies were carried out. If the high strength titanium alloy pipe is produced by direct cold rolling process, the production cost can be greatly reduced and the high performance titanium alloy application can be satisfied.　

The billet is rolled into tubes with a total deformation of 70% by two or three passes respectively. Vacuum annealing at 800℃×1h was carried out between passes. The cooling method was that the furnace was cooled to 500℃ and then air cooled to room temperature and the microstructure and properties were observed. It was concluded that:　　

Under the condition of small deformation, the wall thickness deviation is small and the surface roughness gradually decreases. The wall thickness deviation caused by large deformation will affect the wall thickness deviation of the pipe after subsequent rolling.　　

When the total deformation is the same, the more rolling passes are operated, the greater the elongation and hardness of the pipe, and the higher the strength. Good comprehensive performance.　

When rolling with large deformation, the flow of material is banded, while when rolling with small deformation, the flow of material is bunched. Under the condition of interpass heat treatment and the following rolling process are the same, the deformation of the microstructure of the pipe cut with large deformation is more serious.　　

Small deformation has little effect on anisotropy of pipe. The anisotropy of mechanical properties in multi-pass rolling has some fluctuation.