Forging category
作者：admin 来源：本站 发布时间：2019-03-29 02:22:56 浏览量：
As mentioned above, according to the forging temperature, it can be divided into hot forging, warm forging and cold forging. According to the forming mechanism, forging can be divided into free forging, die forging, rolling ring, and special forging.
1. Free forging
Refers to a method of processing a forging that uses a simple universal tool or an external force directly applied to the blank between the upper and lower anvil of the forging equipment to deform the blank to obtain the desired geometry and internal quality. Forgings produced by the free forging method are called free forgings. Free forging is mainly for the production of forgings with small quantities, and forgings are processed by forging equipment such as forging hammers and hydraulic machines to obtain qualified forgings. The basic processes of free forging include upsetting, drawing, punching, cutting, bending, twisting, misalignment and forging. Free forging is a hot forging method.
2. Die forging
Die forging is divided into open die forging and closed die forging. The metal blank is pressed and deformed in a forging die having a certain shape to obtain a forged piece, and the die forging is generally used for producing a part having a small weight and a large batch size. Die forging can be divided into hot forging, warm forging and cold forging. Warm forging and cold forging are the future development directions of die forging, and also represent the level of forging technology.
According to the material, die forging can also be divided into black metal die forging, non-ferrous metal die forging and powder product forming. As the name implies, the materials are ferrous metals such as carbon steel, non-ferrous metals such as copper and aluminum, and powder metallurgy materials.
Extrusion should be attributed to die forging and can be divided into heavy metal extrusion and light metal extrusion.
Closed die forging and closed upset forging are two advanced processes for die forging. Since there is no flash, the material utilization rate is high. Finishing of complex forgings is possible with one or several processes. Since there is no flash, the area of ??force applied to the forging is reduced and the required load is also reduced. However, care should be taken not to completely limit the blank. To this end, the volume of the blank is strictly controlled, the relative position of the forging die is controlled, and the forging is measured to reduce the wear of the forging die.
3. Grinding ring
Rolling ring refers to the production of ring-shaped parts of different diameters by special equipment grinding machine, and also used to produce wheel-shaped parts such as automobile wheels and train wheels.
4.Special forging
Special forging includes roll forging, cross wedge rolling, radial forging, liquid die forging, etc. These methods are more suitable for the production of parts with special shapes. For example, roll forging can be used as an effective preforming process to significantly reduce subsequent forming pressures; cross wedge rolling can produce steel balls, drive shafts, etc.; radial forging can produce large forgings such as barrels and step shafts.
5. Forging die
According to the movement mode of the forging die, the forging can be divided into pendulum, pendulum forging, roll forging, cross wedge rolling, boring ring and cross rolling. Swing, swivel and shackle can also be used for precision forging. In order to improve the utilization of materials, roll forging and cross rolling can be used as a front-end process for slender materials. The same rotary forging as free forging is also partially formed, which has the advantage that it can be formed in the case of a smaller forging force than the forging size. This type of forging, including free forging, expands from the vicinity of the mold surface to the free surface during processing. Therefore, it is difficult to ensure accuracy. Therefore, the movement direction of the forging die and the swaging process can be controlled by computer. The forging force obtains products with complex shapes and high precision, such as forgings such as steam turbine blades with large variety and large size.
The die motion and degree of freedom of the forging equipment are inconsistent. According to the characteristics of the bottom dead center deformation, the forging equipment can be divided into the following four forms:
Limiting the form of forging force: hydraulic press that directly drives the slider.
Quasi-stroke limit mode: hydraulic press that drives the crank-link mechanism.
Stroke Limiting Mode: Mechanical presses that drive the slider with cranks, connecting rods and wedge mechanisms.
Energy limiting method: a screw and friction press using a screw mechanism.
In order to achieve high accuracy, care should be taken to prevent overload at the bottom dead center, control speed and mold position. Because these will have an impact on forging tolerances, shape accuracy and forging die life. In addition, in order to maintain accuracy, you should also pay attention to adjust the slider rail clearance, ensure the stiffness, adjust the bottom dead center and use the auxiliary transmission and other measures.
There are also slider vertical and horizontal movements (for forging of the elongated parts, lubrication cooling and high-speed production of parts forging), the use of compensation devices can increase the movement in other directions. Different methods are used, the required forging force, process, material utilization, production, dimensional tolerance and lubrication cooling method are different. These factors are also factors that affect the level of automation.
