Forging is a processing method that uses forging machinery to apply pressure to metal billets to cause permanent plastic deformation in a plastic state, thereby obtaining a processing method with a specific shape, size and excellent mechanical properties. Its core is to change the internal structure of the metal through external force, eliminate defects such as loose cast state and pores generated during the smelting process, refine the metal grains, and make the structure dense, while retaining complete metal streamlines, thereby improving the comprehensive performance of the material.

Forging Process And Key Technologies

The forging process covers six core links: material selection, blanking, heating, deformation, cooling, and inspection. The specific process is as follows:

Material selection: Select metal materials such as carbon steel, alloy steel, aluminum, magnesium, and copper according to product requirements. Iron-based, nickel-based, and cobalt-based high-temperature alloys will also be used in high-end fields.

Blanking: Cut the metal material into billets of specified size to ensure shape and size accuracy.

Heating: Heat the billet to a plastic state through electric furnaces, gas furnaces and other equipment. Temperature control directly affects the forging quality. For example, the hot forging temperature is usually higher than 800℃, the warm forging temperature is between 300-800℃, and the cold forging temperature is carried out at room temperature.

Deformation:

Free forging: Use general tools (such as forging hammers, hydraulic presses) to directly apply external force to the blank, and obtain the desired shape through upsetting, drawing, punching and other processes, which is suitable for single-piece or small-batch production.

Die forging:Put the heated metal into the die and deform it under pressure or impact force. It is divided into open die forging and closed die forging. Closed die forging has no flash and high material utilization rate, which is suitable for batch production of complex parts.

Special Forging:

Including roll forging, wedge cross rolling, radial forging, etc., suitable for the production of special-shaped parts, such as steel balls, transmission shafts, barrels, etc.

Cooling: After forging, it needs to be quickly cooled to room temperature, and the cooling speed and uniformity are controlled to avoid defects such as quenching cracks.

Inspection: 

Ensure that the quality of forgings meets the standards through dimensional measurement, metallographic analysis, hardness testing and other means.

Performance Advantages And Application Value of Forging

The forging process gives metal materials the following significant performance advantages:

Excellent mechanical properties: Forgings have better strength, toughness, and fatigue resistance than castings, and can withstand heavy loads and impact loads, such as machine tool spindles, transmission shafts, etc.

Dense metal structure: During the forging process, defects such as pores and shrinkage are pressed together, the grains are refined, and the uniformity of the structure is improved, thereby improving the reliability of the material.

Reasonable fiber structure: By controlling the deformation direction, the metal streamlines are distributed along the contour of the parts to enhance the impact resistance.

High dimensional stability: The shape and size accuracy of forgings are high, and the performance of parts in the same batch is uniform, which is suitable for high-precision requirements.

Industry Applications And Typical Scenarios of Forging

Forging technology is widely used in the following fields and has become the cornerstone of modern industry:

Automobile industry: Key components such as steering knuckles, front beams, and car hooks are mostly forged. According to statistics, forgings account for 80% of automobiles.

Energy equipment: Thermal power plants: Core components such as rotors, impellers, retaining rings, and spindles rely on forging technology.

Hydro-turbine generator: Large forgings such as main shaft and intermediate shaft ensure stable operation of equipment.

Shipbuilding: Crankshaft, tail shaft, rudder stock and other heavy-loaded parts are forged to improve reliability.

Rail transit: Locomotive axles, wheels, leaf springs and other parts adopt forging technology, accounting for 60%.

Military industry: Key parts of weapons and equipment such as gun barrels, door bodies, and breech blocks rely on forging technology, and forgings account for 65% of tanks.

Metallurgical machinery: High-load parts such as cold rolling rollers, hot rolling rollers, and herringbone gear shafts are optimized through forging.

Pressure vessels: Cylinders, kettle ring flanges, heads and other parts adopt forging technology to ensure pressure safety.

Engineering machinery: Core components such as hammer heads, hammer rods, and hydraulic press columns rely on forging technology.