Production Process of Forged Flange Parts

The flange production process is mainly divided into forging, casting, cutting and rolling. The flange sealing forms are: raised face (RF), concave face (FM), convex face (M), tenon face (T), groove face (G) and full face (FF).  

The flange blanks cast by casting flange and forging flange have accurate shape and size, small processing capacity and low cost, However, casting defects (air holes, cracks, inclusions, because the flange replaces the forged section during quenching and cooling, the cooling speed varies with the section thickness of different parts, and the cooling speed gradually decreases from the surface. The forged section is the main reason for the inconsistency of the microstructure and mechanical properties of different parts; cast flange: the internal structure is irregular (such as cutting parts, the streamline degree is small); The forging is not easy to rust, and the forging shape and structure are compact, superior to the performance; If the forging process is not suitable, the grain size of the casting will be large or uneven. Forging cost is higher than casting flange. Forgings can withstand higher shear force and tension than castings. The advantages of forgings are that the internal structure is uniform, and there are no harmful defects such as air holes and inclusions in the castings.  

The difference between cast flange and forged flange lies in the production process. For example, centrifugal flange is a cast flange. Centrifugal flange belongs to the precision casting method of flange production. Compared with the ordinary sand casting flange, the centrifugal flange has a much smaller structure, and its quality has also been greatly improved. First of all, we need to know the process and products of centrifugal flange production and centrifugal casting flat welding flange. Its feature is that the product is processed through the following process steps: raw steel is selected to be melted in the medium frequency signal furnace to make the temperature of steel reach 1600-1700 ° c; Preheat the metal mould to 800-900 ° c and keep the constant temperature; Start the centrifuge, and inject molten steel into the metal mold after the preheating step. The castings shall be naturally cooled to 800-900 ° c and kept for 1-10 minutes; (5) Cool with water to near room temperature and remove the casting.  

Let's have a look at the production process of flange forgings: forging process generally consists of the following processes: blanking, heating, forming and forging cooling of high-quality blanks. The forging process includes free forging, die forging and mould forging. During the production process, different forging methods are selected according to the quality of forgings and the number of production batches. The free forging has low productivity and large machining allowance, but the tools are simple and versatile, which is widely used to forge single pieces and small batches of forgings with simple shape. Free forging equipment includes air hammer, steam air hammer and hydraulic press, which are suitable for medium and small forging production and large forging production respectively. Die forging has high productivity, simple operation, and is easy to realize mechanization and automation. Die forgings have the advantages of high dimensional accuracy, small machining allowance and reasonable fiber structure distribution, which can further improve the service life of parts. The basic process of free forging is: in the process of free forging, the shape of the forging is gradually forged into a blank through some basic deformation processes.

The basic processes of free forging include upsetting, stretching, punching, twisting and cutting.  

1. Upsetting refers to the process of axial forging the raw blank to reduce its height and increase its cross section. This process is commonly used for forging gear blanks and other types of disk forgings. Upsetting is divided into full upsetting and local forging.  

2. Stretching: the process of increasing the blank length and reducing the forging section. It is often used to create axial conditions, such as lathe spindles and connecting rods. The forging process of punching or piercing a blank with a punch.  

3. Punching: the forging process of punching through holes or through holes on the blank with a punch.

4. Torsion: a forging process in which one blank is rotated to another at an angle.   

5. Cutting: forging process cutting and cutting square billet or cutting head.  

Flanges are indispensable in our work and life, including gas, heat, nuclear, electric power, petroleum, chemical, shipbuilding, urban construction and other industries. We are also very strict with the surface treatment process of flanges, including primary color, antirust oil, paint, zinc plating, etc., which can be customized according to customer requirements.