The so-called forging, in fact, the structure is similar to our current master blacksmith, and its original ideal is common. It's just that one applies pressure to the material through a machine, while the blacksmith forges it manually. The ultimate goal is to obtain products with better mechanical properties, shapes and sizes.



Why can we only use forging? Because forging can offset the as-cast porosity defects caused by metal smelting, it can better allow the microstructure to have better physical properties.



Temperature and classification required for forging
Since most of the materials are steel, we define it based on the recrystallization temperature of steel. The recrystallization temperature of common steel is 727℃. Therefore, 800°C is usually used as the dividing line. Let the temperature >800℃ be called hot forging; and the temperature between 300 and 800℃ is called semi-hot forging, and the one that is performed at room temperature without heating is called cold forging. Most of the forgings are hot forging, and semi-hot forging and cold forging are generally used for parts such as automobiles and general machinery. The main reason is that semi-hot forging and cold forging can save costs and materials.



Forging is classified by molding
It can be divided into: free forging, die forging, ring rolling, special forging, etc.

1. Free forging: The basic procedures of free forging include upsetting, drawing, punching, cutting, bending, twisting, shifting and forging.

2. Die forging: There are open die forging and closed die forging. Refers to the forging of materials that are deformed under pressure in the cavity. Die forging is generally used to produce parts with low weight and large batches.



3. Ring rolling: refers to the use of ring rolling machines to obtain ring products with different diameters, which are used to produce wheel-shaped parts such as automobile hubs and train wheels.

4. Special forging: It includes roll forging, cross wedge rolling, radial forging, liquid die forging and other methods, most of which are suitable for the production of parts with special shapes.