Influence Of Surface Condition Of Forging Blanks And Tools On Plasticity And Deformation Resistance

In the forging deformation, the billet is contacted with the tool or the die chamber, and its surface condition has different influence on the plasticity and the deformation resistance.

1, the impact of the surface condition of forging blanks, the more smooth the surface of the billet, the greater the limit deformation when upsetting, on the contrary, the bad material surface roughness or micro-cracks, inclusions and other defects, deformation over the towel stress concentration, plastic low lead to cracking, especially in cold deformation billet surface quality is particularly important. 2, tool, the impact of the surface conditions of the mold, metal forgings and tools or the die in the forging process between the relative sliding, resulting in friction, so that forging deformation resistance increased, plastic reduction.

Therefore, the friction has great influence on the plasticity and deformation resistance of the deformed forgings. 3, the impact of billet size, in the forging of the billet belongs to the deformation body. The size of the deformed body also has influence on the plasticity and deformation resistance, the larger the size of the variable body, the more uneven the chemical composition and microstructure, the greater the deformation resistance when forging; but it is generally believed that if the volume of the deformed body increases and the volume exceeds a certain critical value, the plasticity and deformation resistance of the forgings will no longer decrease with the increase of volume.