Forging is a forming method that applies external force to titanium metal blanks (excluding plates) to cause plastic deformation, change size, shape and improve performance, and is used to manufacture mechanical parts, workpieces, tools or blanks. In addition, according to the movement mode of the slider, there are vertical and horizontal movement of the slider (for forging of elongated parts, lubrication and cooling, and forging of parts produced at high speed). The use of compensation devices can increase movement in other directions. The above methods are different. The required forging force, process, material utilization, output, dimensional tolerance and lubrication and cooling methods are different. These factors are also factors that affect the level of automation.
Forging can be divided into free forging, upsetting, extrusion, die forging, closed die forging, and closed upsetting forging according to the movement method of the blank. Closed die forging and closed upset forging have no flash, so the material utilization rate is high. With one process or several processes, it is possible to finish the finishing of complex forgings. Since there is no flash, the bearing area of the forging is reduced, and the required load is also reduced. However, it should be noted that the blank cannot be completely restricted. For this reason, the volume of the blank should be strictly controlled, the relative position of the forging die and the measurement of the forgings should be controlled to reduce the wear of the forging die.
According to the movement mode of the forging die, forging can be divided into swing rolling, swing rotary forging, roll forging, cross wedge rolling, ring rolling and cross rolling. Swinging, swinging forging and rolling rings can also be processed by precision forging. In order to improve the utilization rate of materials, roll forging and horizontal rolling can be used as the front-end processing of slender materials. Rotary forging, which is the same as free forging, is also partially formed. Its advantage is that it can be formed even when the forging force is small compared to the size of the forging. In this forging method, including free forging, the material expands from the vicinity of the die surface to the free surface during processing. Therefore, it is difficult to ensure accuracy. Therefore, the computer can control the movement direction of the forging die and the rotary forging process. The forging force can obtain products with complex shapes and high precision, such as forgings of steam turbine blades with many varieties and large sizes.
In order to obtain high accuracy, care should be taken to prevent overload at the bottom dead center, and control the speed and mold position. Because these will affect the tolerance of forgings, shape accuracy and forging die life. In addition, in order to maintain accuracy, attention should also be paid to adjusting the slider rail clearance, ensuring rigidity, adjusting the bottom dead center and using auxiliary transmission devices and other measures.
Titanium forging materials are mainly pure titanium and titanium alloys of various compositions. The original state of the material is bar stock, ingot, metal powder and liquid metal. The ratio of the cross-sectional area of the metal before deformation to the cross-sectional area after deformation is called the forging ratio. Correct selection of forging ratio, reasonable heating temperature and holding time, reasonable initial forging temperature and final forging temperature, reasonable deformation amount and deformation speed have a great relationship with improving product quality and reducing costs. General small and medium-sized forgings use round or square bar stock as blanks. The grain structure and mechanical properties of the bar are uniform and good, the shape and size are accurate, and the surface quality is good, which is convenient for mass production. As long as the heating temperature and deformation conditions are reasonably controlled, forgings with excellent performance can be forged without large forging deformation.
Titanium Material Forging Method
