Forging, as an important metal processing method, has existed for thousands of years. With the development of technology, forging processes have differentiated into many types, and each forging method has its unique advantages and applicable fields. In modern industry, forging is mainly divided into several forms such as free forging, die forging, precision forging, warm forging and cold forging. This article will introduce in detail the characteristics, advantages and disadvantages of various forging processes and their practical applications.

1. Open Die Forging

Features:

Free forging is the most traditional forging method. The metal material is placed between two plates and the material is plastically deformed by hammering or pressing. Since there is no mold restriction, the operation is flexible and workpieces of various shapes and sizes can be produced.

Advantages:

· Flexible operation, suitable for various metal materials, including steel, aluminum, copper, titanium, etc.

· Can manufacture super-large workpieces, such as large shafts, rollers, wheels, etc.

· The processing cost is relatively low, especially for small batches or single products

Disadvantages:

· Low dimensional accuracy, usually requiring subsequent machining to achieve the required size and shape.

· Low production efficiency, complex workpieces require multiple hammering or pressing.

· Relatively large material waste during the production process.

Application:

Free forging is often used to manufacture large mechanical parts, such as the spindle of heavy machinery, flanges of pressure vessels, and anchors in the shipbuilding industry.

2. Closed Die Forging

Features:

Die forging is a forging process formed by a die. The metal material is placed in the die cavity, and the material is filled with the die through impact or pressure, and finally formed. Die forging can produce parts with complex geometric shapes and good dimensional accuracy.

Advantages:

· High precision, which can reduce the need for subsequent machining.

· High production efficiency, suitable for mass production.

· Excellent mechanical properties of parts, dense internal structure, and strong fatigue resistance.

Disadvantages:

· High mold manufacturing cost, suitable for mass production, not suitable for small batch or single piece production.

· The mold design is complex and the cycle is long, requiring precise mold design.

· Large or super-large parts are difficult to achieve through die forging.

Application:

Die forging is widely used in industries such as automobiles, aerospace, railways and petroleum to produce high-precision parts such as gears, connecting rods, crankshafts, turbine blades, etc.

3. Precision Forging

Features:

Precision forging is developed on the basis of die forging. Its goal is to obtain workpieces close to the final finished product size during the forging process, thereby reducing or even eliminating subsequent processing. Precision forging requires high mold design and advanced processing equipment.

Advantages:

· The surface quality and dimensional accuracy of the parts are high, and the subsequent processing volume is extremely small.

· High material utilization, close to the net shape process, and less waste.

· Good product consistency, suitable for the production of small parts with complex shapes.

Disadvantages:

· The precision requirements for the mold are extremely high, and the mold cost is high.

· The scope of application is limited, mainly used for the production of small precision parts.

· High requirements for forging equipment and high investment costs.

Application:

Precision forging is mostly used for the production of high-precision and complex structural parts, such as gears, bearings and key parts in aircraft engines.

4. Warm Forging

Features:

Warm forging refers to a forging process performed in the medium temperature range, and the general processing temperature is between 600°C and 900°C. Warm forging strikes a balance between plasticity and strength, making it easy to form materials while avoiding the common work hardening problems in cold forging.

Advantages:

· Easier material forming, less die wear, and longer die life.

· High dimensional accuracy, less prone to cracks in cold forging and excessive deformation in hot forging.

· Low energy consumption, energy-saving and environmentally friendly compared to hot forging.

Disadvantages:

· High equipment requirements and require a precise temperature control system.

· The forming process is more complicated, and the selection of materials and processes is more demanding.

· For some high-strength alloy materials, the application of warm forging technology has certain limitations.

Application:

Warm forging is suitable for the production of small and medium-sized parts, especially in occasions such as automotive parts, bearings and gears that have high requirements for size and surface quality.

5. Cold Forging

Features:

Cold forging is a forging process performed at room temperature and is often used for mass production of small parts. Cold forging does not involve heating process, so extremely high dimensional accuracy and surface quality can be obtained.

Advantages:

High dimensional accuracy, excellent surface quality, no need for subsequent processing.

Increased strength, due to work hardening, the internal structure of the material is more compact.

Low energy consumption, eliminating the heating process and saving energy.

Disadvantages:

Due to forming at low temperature, the plasticity of the material is low and it is easy to crack.

The process is complicated, the mold is easy to wear, and the mold life is short.

It is only suitable for small and simple-shaped parts, and complex parts are difficult to achieve cold forging.

Application:

Cold forging process is widely used in the production of small parts such as fasteners, bolts, nuts, bearings, gears, etc., especially suitable for the automotive and electronics industries.

6. Isothermal Forging

Features:

Isothermal forging refers to a forging method in which the temperature of the workpiece and the die is kept constant throughout the forging process. It is usually used in the production of precision parts of difficult-to-process materials such as high-temperature alloys and titanium alloys.

Advantages:

Precise control, uniform deformation of parts, and high surface quality.

Avoids the problem of local cooling of the die and workpiece caused by temperature difference.

Can achieve forging of parts with complex shapes and reduce material waste.

Disadvantages:

The process is complex, the temperature control requirements are strict, and the equipment is expensive.

The forging cycle is long and the production efficiency is low.

Suitable for the production of high value-added parts with high cost.

Application:

Isothermal forging is mainly used in fields such as aerospace, nuclear energy, etc. that have extremely high requirements for material properties, especially the processing of titanium alloys, nickel-based high-temperature alloys, etc.

Each forging process has its own unique advantages and disadvantages and is suitable for different application scenarios. Free forging is suitable for the processing of large and complex parts, while die forging and precision forging are more suitable for mass production of high-precision parts. Warm forging and cold forging have shown their advantages in energy saving and efficient production, while isothermal forging focuses on the precision processing of high-performance materials. According to the design requirements, batch size and material characteristics of the product, the rational selection of forging process can significantly improve product quality and reduce production costs.

Generally, after forging is completed, CNC will be used for further processing