Cold heading process is a forging method that uses a mold to upset metal bars at room temperature, usually used to manufacture the heads of screws, bolts, rivets, etc. Next, we will briefly introduce the knowledge about cold heading accuracy.
Reasons for affecting the accuracy of cold heading process:
1.Chemical composition of raw materials: Pure metals have better plasticity than alloys, and impurity elements usually cause brittleness to decrease plasticity. Various alloys have different effects on plasticity.
2.Raw material metallographic structure: Different properties, shapes, sizes, quantities, and distribution states of multiphase structures have varying degrees of impact on plasticity. Defects such as grain and segregation, inclusions, bubbles, and porosity can reduce the plasticity of the metal.
3.Process deformation temperature: As the temperature increases, the plasticity increases, but this increase is not a simple linear increase.
4. Metal strain rate: The increase in strain rate has both a decrease in metal plasticity and an increase in metal plasticity. The combined effect of these two factors ultimately determines the changes in metal plasticity.
5. Deformation mechanics conditions: Compressive strain is beneficial for the development of plasticity, while tensile strain is unfavorable for plasticity. The plastic processing method with a three-dimensional compression principal stress diagram and a two-dimensional compression principal strain diagram is extremely conducive to the development of metal plasticity.
