Selection of Raw Materials for Cold Heading Machine Workpieces

Cold heading machine is a special equipment mainly used for batch manufacturing of nuts, bolts and other fasteners. Most of them are heavy equipment that exerts pressure on metal, and most of them are equipped with safety protection devices to ensure the safety of equipment and personnel. The chemical composition and mechanical properties of cold heading raw materials of cold heading machine shall conform to the relevant standards of multi station automatic cold heading machine. Common raw materials include copper aluminum alloy, carbon steel, stainless steel, etc. Next, Tianwei will introduce the selection of raw materials for cold heading machine;

1、 Selection of Raw Materials for Cold Heading Machine Workpieces

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

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

(3) The inch accuracy of raw materials shall generally be determined according to the specific requirements and process conditions of the workpiece. Generally speaking, the multi station cold heading machine has low requirements on the dimensional accuracy of the shrinkage and strong shrinkage.

(4) The surface quality of raw materials requires that the lubricating film is dull, and the surface shall be free of scratches, folds, cracks, scratches, rust, oxide skin, pits and other defects.

(5) The total thickness of the radial decarburization layer of the raw material shall not exceed 1% of the diameter of the raw material.

(6) In order to ensure the cutting quality during cold forming, the surface of raw materials shall be hard and the core shall be soft.

(7) Cold heading test shall be carried out for raw materials. Cold work hardening will increase the deformation resistance. The lower the sensitivity of materials to cold work hardening, the better.

2、 Selection of forming oil for cold heading machine

(1) It has excellent extreme pressure lubrication performance, high temperature resistance, extreme pressure wear resistance, rust prevention, high temperature oxidation resistance and stability. Improving the precision and flatness of the machined parts can prevent mold sintering, meet the multi station forming processing of standard parts and non-standard parts, and can be fully competent for cold heading stainless steel parts.

(2) The soot and "floating fog" can be reduced to the minimum, meeting the nut process of forced shrinkage mold.

(3) For workpieces with large deformation, such as hollow, high-strength bolts, sleeves, stainless steel hollow, semi hollow rivets, etc., it has good performance.

(4) The utility model can effectively protect the punch rod (punch needle) and the die, and prolong the service life.

(5) The heat dissipation effect is good, and the local temperature of the workpiece and the mold during the cold forming process is avoided to be too high.

(6) High temperature resistance, not easy to produce sludge. Low odor, low smoke, protect the operating environment.

(7) The forming oil of cold heading machine has certain antirust property, which can meet the antirust requirements between processes.

(8) It can meet the requirements of large deformation cold heading stainless steel and carbon steel forming process.

The above is the selection method of raw materials for cold heading machine process. The use of raw materials that meet the process requirements can effectively avoid the quality problems of the workpiece.