The three-way hot pressure forming is a tube that will be larger than the diameter of three tong, and the diameter of the tube is about three to three diameter, and a hole is opened in the part of the drawing branch. The tube billet is heated and put into the forming mould, and the punching die is put into the tube. Under the action of pressure, the tube is compressed by radial compression. In the radial compression, the metal flows in the direction of the branch and forms a branch under the stretching of the die.
The whole process is formed through the radial compression of the tube and the stretching process of the branch. In contrast to the hydraulic bulge, the metal is compensated by the radial movement of the tube billet, which is also referred to as radial compensation technology. Due to the application of heating, the equipment tonnage of the material is reduced. It is suitable for the materials of low carbon steel, alloy steel and stainless steel. In particular, the large diameter and the wall thickness of the three - pass, usually adopt this forming process.