Cold-formed steel is widely used in buildings, automobiles, equipment, home and office furniture, utility poles, storage racks, grain bins, highway products, drainage facilities, and bridges. Its popularity can be attributed to ease of mass production and prefabrication, uniform quality, lightweight designs, economy in transportation and handling, and quick and simple erection or installation.
In building construction, cold-formed steel products can be classified into three categories: members, panels, and prefabricated assemblies. Typical cold-formed steel members such as studs, track, purlins, girts and angles are mainly used for carrying loads while panels and decks constitute useful surfaces such as floors, roofs and walls, in addition to resisting in-plane and out-of-plane surface loads. Prefabricated cold-formed steel assemblies include roof trusses, panelized walls or floors, and other prefabricated structural assemblies. Cold-formed steel possesses a significant market share because of its advantages over other construction materials and the industry-wide support provided by various organizations that promote cold-formed steel research and products, including codes and standards development that is spearheaded by the American Iron and Steel Institute (AISI).
Cold-formed steel applications can be traced back as early as the 1850s in both the United States and Great Britain. In the late 1920s and early 1930s, cold formed steel entered the building construction arena with products manufactured by a handful of fabricators. Although these products were successful in performance, they faced difficulties with acceptance for two reasons: (1) there was no standard design methodology available, and (2) cold-formed steel was not included in the building codes at that time. Many of the cold-formed steel applications were unable to be used due to the lack of design methodology and product recognition.
Cold-formed steel products are shaped at ambient temperatures from steel sheet, strip plate or flat bars by roll-forming machines, press brakes or bending brake operations. They can be produced in large quantity and at high speed with consistent quality. A typical automated rolling machine can run at a speed range of 75-400 feet per minute, and the products can be as small as a three-quarter inch wide cold-rolled channel section to as big as a thirty-six inch wide roof deck section.
冷弯型钢产品是在环境温度下由钢板、带材或扁钢通过滚压成型机、压闸机或弯闸机操作成型的。它们可以大批量、高速度、高质量地生产。一台典型的自动卷板机可以以每分钟75-400英尺的速度运行，产品可以小到3 / 4英寸宽的冷轧槽段，大到36英寸宽的屋顶甲板段。