Review and Prospect on Forming Technology and New Technology of Cold Rolling Square Rectangular Tube

Review and Prospect on the 30th Anniversary of Chinese Confenfederation of Roll Forming Industry

Square rectangular tube is one kind of cold roll forming steel that has largest output, and it is widely used in many industrial fields. Its forming process can be divided into two kinds: direct forming and circular-to-square forming. Direct forming technology has been widely promoted and applied in China, and the technology level of processing and equipment has been developing continuously. Having experienced several stages, that are, technology introduction, digestion and absorption, and technology innovation, it has realized the development transformation from the initial dependence on imports to the current large volume export. The forming technology and key technology of square rectangular tube and the development trend of new technology are introduced in this article.

Key words: Cold Roll Forming Steel, Square Rectangular Tube, Forming Process, Key Technology, Equipment

1. Square rectangular tubes are widely used

Square rectangular tube is a kind of closed steel that has wide application. Compared with the circular tube with the same cross section, it has the advantages such as high strength, large flexural section modulus and easy assembly, it is stable and beautiful, and is widely used in engineering machinery, vehicle, subway, shipbuilding and other industries. Especially in the construction industry, large square rectangular tubes become the main load-bearing structural components in steel structure buildings.

Square rectangular tubes are usually manufactured by the way of cold roll forming or roller continuous molding. Because of the high productivity of cold roll forming, the production line of welded pipe can produce products without interruption. With high material yield and small head loss, so it can be widely used in mass production. Many cold roll forming steel production enterprises in China regard the square rectangular tubes as the main product type.