Hot Forging/Cold Forging Processing: Selecting Processes on Demand to Adapt to Diverse Material Requirements

Hot Forging/Cold Forging Processing: Selecting Processes on Demand to Adapt to Diverse Material Requirements

In the manufacturing of key components in industries such as automotive, aerospace, and construction machinery, forging processing directly determines the mechanical properties and service life of workpieces. Different materials like carbon steel, alloy steel, and aluminum alloy have significantly distinct physical properties, and a single forging process cannot meet all forming requirements. Hot forging and cold forging processing, with their complementary technical characteristics, form a "dual-process system" that adapts to diverse materials and performance requirements, becoming a core solution for high-quality forging production.

Hot forging is the preferred process for high-hardness and high-toughness materials, with its core advantage lying in "high-temperature softening + large deformation". It heats the blank to 800-1200℃ (adjusted according to the material), which greatly reduces the yield strength of the material and improves its plasticity. This enables the one-time forming of complex workpieces such as large crankshafts and gear blanks made of materials like high-carbon steel and alloy steel. The high-temperature forming process also eliminates internal defects such as material porosity and refines grain structure, increasing the impact toughness of the workpiece by more than 30% compared to castings.

Cold forging, on the other hand, excels in processing low-hardness and high-plasticity materials, characterized by "room-temperature forming + high precision". It does not require heating; instead, it directly causes plastic deformation of the blank through high-pressure equipment at room temperature. For materials such as aluminum alloy, copper alloy, and low-carbon steel, cold forging can achieve near-net forming, with dimensional tolerance controlled within ±0.02mm and surface roughness reaching Ra1.6μm, reducing subsequent machining by more than 60%. The work hardening effect during processing also increases the surface hardness of the workpiece by 20%-40%, making it suitable for manufacturing high-precision components such as automotive bolts and bearing rings.

The rational selection of these two processes depends on material characteristics and performance requirements. For example, in the production of automotive engine connecting rods, the complex-shaped rod body adopts hot forging to ensure toughness, while the high-precision bolt hole uses cold forging to ensure accuracy. In the processing of aerospace titanium alloy components, hot forging is first used for rough forming to break the cast structure, followed by cold forging for finishing to improve surface quality. This not only adapts to the special properties of titanium alloy but also balances performance and precision.

Hot forging and cold forging processing form a complementary system with their respective advantages. By selecting processes based on material type, performance requirements, and structural complexity, they not only solve the forming problems of diverse materials but also ensure the quality and efficiency of forgings. This flexible process selection mechanism has become a key support for the high-quality development of the forging industry.