Analysis Of Domestic Cold Roll Forming Technology

Analysis Of Domestic Cold Roll Forming Technology

In China, since the beginning of the construction of cold-formed units in the late 1950s, it has experienced a tortuous process of development and adjustment. There were only 6 at the end of the 1970s. In the 1980s, China`s cold-formed steel developed rapidly, and by 1982, the output was only 16,000 tons. By 1989, more than 20 manufacturers across the country had an output of more than 300,000 tons and a design capacity of more than 600,000 tons. Among them, 14 key plants in the metallurgical system, 45 sets of units, and cold-formed steel varieties and specifications are also increasing. There are more than 800 species. Under the favorable form of reform and opening up, the national economic construction has put forward new requirements on the variety and quality of steel.

The advantages of cold-formed steel have gradually been recognized and accepted by people, and the production of cold-formed steel has achieved greater development. So far, there are more than 100 sets of cold bending units, with an annual production capacity of 1.5 million tons and a total of more than 1,000 varieties and specifications. For example: Shanbaotou Design and Research Institute developed a medium-Φ219mm medium-diameter welded pipe forming unit, which is a new type of roll forming unit, developed by Shanbaotou Design and Research Institute to digest and absorb some advanced foreign technologies and the specific conditions of the domestic market, namely the CR unit (composite roll mill). The characteristics of the unit are:

(1) The rough forming section of cold bending forming adopts a combination of shared rolls and replacement rolls. When changing product specifications, the rolls of some stands do not need to be replaced, which can save some rolls in reserve.

(2) The combined roll sheet for flat rolls, the rough forming section is six racks, the vertical roll group rolls are arranged obliquely, the volume of the car roll is small, the weight of the roll is more than 1/3 less than the traditional Roll Forming Machine, and the equipment structure is more compact.

(3) The roll profile is simple, easy to manufacture and repair, and the roll repetition rate is high.

(4) The cold bending forming is stable, the rolling mill has strong applicability to the forming of thin-walled tubes and rear wall tubes, and the product specifications range are wide. The first set of CR-Φ219 forming unit designed by the institute was officially put into production in Tianjin Jinhai Joint Steel Pipe Plant in August 1992. However, no matter in terms of output, quality, variety, consumption and application fields, or in terms of equipment level and technological level, there is a big gap with foreign developed countries, and it is extremely disproportionate to the status of a country with an annual output of nearly 100 million tons of steel. It can be predicted that cold-formed steel will have a greater development in my country.