Production Process and Differences of Industrial Forged Flanges

First, the Forged Flange Production Process

The forging process generally consists of the following steps: selecting high-quality steel billets, heating, forming, and cooling after forging. Forging methods include free forging, die forging, and mold forging. Different forging methods are selected based on the size of the forging and the production batch.

Free forging has low productivity and a large machining allowance, but the tools are simple and versatile, so it is widely used for forging simple single-piece and small-batch forgings. Free forging equipment includes air hammers, steam-air hammers, and hydraulic presses, suitable for small, medium, and large forgings, respectively. Die forging has high productivity, simple operation, and is easily mechanized and automated. Die forgings have high dimensional accuracy, small machining allowance, and a more reasonable fiber structure distribution, which can further improve the service life of the parts.

Basic Steps of Free Forging: In free forging, the shape of the forging is gradually formed from the billet through a series of basic deformation steps. The basic processes of free forging include upsetting, drawing, punching, bending, and cutting.

1. Upsetting: Upsetting is the process of forging the original billet axially, reducing its height, and increasing its cross-section. This process is commonly used for forging gear blanks and other disc-shaped forgings. Upsetting is divided into full upsetting and partial upsetting.

2. Drawing: Drawing is a forging process that increases the length of the billet and reduces its cross-section. It is usually used to produce shaft blanks, such as lathe spindles and connecting rods.

3. Punching: A forging process that uses a punch to punch through or through holes in the billet.

4. Bending: A forging process that bends the billet into a certain angle or shape.

5. Twisting: A forging process that rotates one part of the billet relative to another part by a certain angle.

6. Cutting: A forging process that divides the billet or removes the blank end.

Second, the difference between cast and forged flanges

Cast flanges have accurate blank shapes and dimensions, require less machining, and are lower in cost, but they have casting defects (porosity, cracks, inclusions); the internal structure of castings has poorer streamline (even worse if it's a machined part).

Forged flanges generally have lower carbon content than cast flanges and are less prone to rust. Forgings have better streamlining, a denser structure, and superior mechanical properties compared to cast flanges.

Improper forging processes can also result in large or uneven grains, hardening cracks, and forging costs are higher than cast flanges.

Forgings can withstand higher shear and tensile forces than castings. The advantage of castings is that they can be made into more complex shapes at a lower cost; the advantage of forgings is their uniform internal structure and the absence of harmful defects such as porosity and inclusions found in castings. The production process can also distinguish between cast and forged flanges; for example, centrifugal flanges are a type of cast flange.