Origin of Cold Forging Development

Cold die forging, cold extrusion, cold upsetting and other plastic processing. The cold forging of the die manufacturer is a forming process below the recrystallization temperature of the material and a forging process below the recovery temperature. In production, it is customary to call forging without heating blank as cold forging. Cold forging materials are mostly aluminium and some alloys, copper and some alloys, low carbon steel, medium carbon steel and low alloy structural steel with small deformation resistance and good plasticity at room temperature. Cold forgings have good surface quality and high dimensional accuracy, which can replace some cutting processes. Cold forging can strengthen metal and improve the strength of parts.

Modern cold forging technology began at the end of the 18th century. Since the French Revolution, when lead was extruded from holes into bullets, extrusion has become a new term and a new process.

In 1830, France began to reverse extrude lead and tin pipes by mechanical press.

In 1886, an injection moulded hollow bottom shell appeared in France. All of the above belong to hot forging and hot pressing, but they are the basis of cold forging.

In 1900, L. E. Hooker of the United States patented the forward extrusion method for hollow parts of non-ferrous metal materials such as lead, zinc, aluminium and brass, and manufactured brass suit buttons. During the First World War, the United States manufactured brass cartridges by forward extrusion and Germany developed steel cartridges.

In 1935, the Germans adopted the phosphating treatment method and new lubricants developed the previous year, and manufactured steel bullets by extrusion, which became a military secret during World War II.

In 1940, the cold extrusion of steel shell and simplified parts appeared. In the early 1950s, China and other countries began to introduce it from abroad. It was first used in cold forging of bicycle parts. Then cold forging entered the production industry of motorcycles and textile machinery. In the 1960s, it entered the automobile industry, electrical industry and other fields. Since the 1980s, Japan's cold forging technology has made important achievements in the application and research of high precision and complex shape parts processing. It has been used in some composite materials, equipment manufacturing and automotive parts.

In 2002, Guangdong, Zhejiang, Shanghai and Jiangsu all used this equipment to forge lamps, automotive fittings and generator covers. With the diffusion of technology, it was circulated by the manufacturing industry.