The forging process generally consists of the following processes, that is, selecting high-quality billets for blanking, heating, forming, and cooling after forging. Forging methods include free forging, die forging, and membrane forging. During production, different forging methods are selected according to the quality of forgings and the number of production batches.
Free forging has low productivity and a large machining allowance, but the tools are simple and versatile, so it is widely used for forging single-piece and small-batch forgings with relatively simple shapes. Free forging equipment includes air hammers, steam-air hammers, hydraulic presses, etc., which are suitable for the production of small, medium, and large forgings. Die forging has high productivity, simple operation, and easy mechanization and automation. Die forgings have high dimensional accuracy, a small machining allowance, and a more reasonable fiber structure distribution of forgings, which can further improve the service life of parts.
The basic process of free forging: during free forging, the shape of the forging is gradually forged from the blank through some basic deformation processes. The basic processes of free forging include upsetting, drawing, punching, bending, and cutting.
1. Upsetting Upsetting is an operation process in which the original billet is forged in the axial direction to reduce its height and increase its cross-section. This process is often used for forging gear blanks and other disc-shaped forgings. Upsetting is divided into two types: total upsetting and partial forging.
2. Elongation Elongation is a forging process that increases the length of the blank and reduces the cross-section. It is usually used to produce shaft blanks, such as lathe spindles and connecting rods.
3. Punching is a forging process in which a punch is used to punch out a through hole or a non-through hole on the blank.
4. Bending is a forging process in which the billet is bent into a certain angle or shape.
5. Twisting is a forging process in which one part of the blank is rotated at a fixed angle relative to another part.
6. The forging process of cutting and dividing the billet or cutting off the head.
(2) Die forging: Die forging is called model forging. It is formed by placing the heated blank in a forging die fixed on the die forging equipment.
1. The basic process of die forging process: blanking, heating, pre-forging, final forging, punching and skinning, trimming, quenching and tempering, and shot peening. Common processes include upsetting, drawing, bending, punching, and forming.
2. Commonly used die forging equipment includes die forging hammers, hot die forging presses, flat forging machines, and friction presses.
In layman's terms, forged steel flanges are of better quality, generally produced by die forging, with fine crystal structure and high strength, but of course, the price is also more expensive. Both cast steel flanges and forged steel flanges are commonly used manufacturing methods for steel flanges. Depending on the strength requirements of the parts to be used, if the requirements are not high, turning steel flanges can also be used.
(3) Cutting steel flange: directly cut out the steel flange disc with the inner and outer diameter and thickness of the steel flange on the middle plate, and then process the bolt holes and waterline. The steel flanges produced in this way are called cut steel flanges, and the maximum diameter of such steel flanges is limited to the width of the middle plate.
(4) Coiled steel flange: The process of cutting the middle plate and then rolling it into a circle is called rolling, which is mostly used in the production of some large steel flanges. After the rolling is successful, it is welded, then flattened, and then the waterline and bolt holes are processed.