Selection Of Raw Materials For Various Parts Of Cold Heading Machine

(1) The raw material must be spheroidized and annealed, and the metallographic structure of the material is spherical pearlite.

(2) In order to reduce the cracking tendency of the material as much as possible, and improve the service life of the mold, it is also required that the cold drawn material have the lowest possible hardness to improve the plasticity.

(3) The precision of the raw materials should generally be determined according to the specific requirements of the product and the process conditions. Generally speaking, the multi-station cold heading machine has lower requirements for reduced diameter and forced dimensional accuracy.

(4) The surface quality of raw materials requires that the lubricating film is dull and dark, and the surface must not have defects such as scratches, folds, cracks, napping, rust, oxide skin, and pits.

(5) The total thickness of the decarburized layer in the radial direction of the raw material is required to not exceed 1% of the diameter of the raw material.

(6) In order to ensure the cutting quality during cold forming, the raw material is required to have a harder surface and a softer core.

(7) The raw materials should be subjected to a cold heading test, and the deformation resistance is increased due to cold work hardening. The lower the sensitivity of the material to cold hardening, the better.