Hot forging and cold forging are two different metal processing technologies. They have significant differences in temperature, mechanical properties and application range.
First of all, hot forging is a forging process performed at high temperatures, which usually reaches or exceeds the recrystallization temperature of the metal. This high-temperature state significantly reduces the metal's resistance to deformation during the forging process and improves the metal's toughness, making it easier to process and form.
In contrast, cold forging is forging performed at room temperature or at a relatively low temperature. It usually achieves high tightness and stability of the product by adjusting the forming temperature of the metal, or performing water quenching, natural air cooling, etc. after hot processing. Although cold forging has lower costs, its production efficiency is relatively low.
In terms of mechanical properties, hot forging, due to its high plasticity brought about by its high temperature state, helps to form a uniform and good-quality granular structure inside the metal, which is less susceptible to the influence of residual stress and exhibits better performance. In cold forging, due to the large deformation resistance and poor plasticity of the material during forging, the hardness and brittleness of the forged parts often increase, which is also one of the reasons for its low output.
In terms of scope of application, hot forging is more suitable for materials with low strength, high toughness, and easy deformation, such as steel and copper. These materials are easily deformed at high temperatures, so hot forging is an ideal processing method. Cold forging is more suitable for materials with high strength, low toughness, and difficulty in deformation, such as aluminum alloys and titanium alloys. These materials maintain their high strength and stability during the cold forging process to meet specific usage requirements.
