Cold forging and hot forging are two core processes of metal plastic processing.
The fundamental difference lies in the processing temperature (whether it exceeds the metal recrystallization temperature), which directly leads to significant differences in process characteristics, applicable materials and final product performance. The following is a detailed comparison and analysis of applicable materials:
| Characteristics | Cold Forging | Hot Forging |
| Temperature range | Room temperature (or slightly above room temperature, usually <30% of the metal recrystallization temperature) | Much higher than the recrystallization temperature (steel: 950-1250°C; aluminum: 350-480°C) |
| Deformation resistance | Extremely large (requires large-tonnage equipment) | Extremely small (about 1/10 of cold forging) |
| Product accuracy | Extremely high (tolerance ±0.05mm) | Low (tolerance ±0.5-2mm, requires subsequent processing) |
| Surface quality | Smooth without oxide scale | With oxide scale and decarburization layer (need to be removed by shot peening/machining) |
| Material strength | Significantly improve strength and hardness through work hardening | Grain refinement improves toughness, and the strength is lower than that of cold forgings |
| Microstructure | Grain deformation and elongation (need annealing to restore plasticity) | Dynamic recrystallization forms equiaxed fine grains |
| Cost structure | High mold cost, eliminating heating and subsequent processing costs | High energy consumption, secondary processing is required, but the mold life is longer |
| Typical applications | Bolts, nuts, precision gears, mobile phone metal parts | Crankshafts, connecting rods, flanges, valves, aviation structural parts |
Cold forging:
pursue dimensional accuracy + strength, used for low-carbon steel/non-ferrous metals with excellent plasticity;
Hot forging:
overcome difficult-to-deform materials + complex structures, sacrificing accuracy in exchange for forming ability;
The core advantage of cold forging is the high strength and high precision brought by room temperature processing, but it is only suitable for materials with good plasticity such as aluminum, low-carbon steel, copper, and pure titanium; hot forging softens the metal at high temperature and can process difficult-to-deform materials such as high-alloy steel and titanium. For example: medium-high carbon steel (C>0.3%), alloy steel/tool steel, high-temperature alloy, molybdenum, tungsten, but oxide scale and dimensional tolerance are pain points. Of course, if you have a need for large-scale forging components, you can choose to cooperate with Mulan Metal. Mulan Metal has 12 years of metal forging experience and is good at various forging processes, helping customers in more than 30 countries complete customized forging processing. Looking forward to your cooperation consultation.
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