1、 Overview of steel structure industry

Steel structure is a structure composed of steel materials, which is one of the main types of building structures. The structure is mainly composed of steel beams, steel columns, steel trusses and other components made of section steel and steel plates, and adopts silane, pure manganese phosphating, water washing, drying, galvanizing and other rust removal and rust prevention processes. Welding seams, bolts or rivets are usually used to connect members or components. Because of its light weight and simple construction, it is widely used in large plants, venues, super high-rise and other fields. It has the following characteristics: 1. High material strength and light weight; 2. Steel toughness, good plasticity, uniform material, high structural reliability; 3. High degree of mechanization in steel structure manufacturing and installation; 4. Good sealing performance of steel structure; 5. Steel structure is heat-resistant but not fire-resistant; 6. Poor corrosion resistance of steel structure; 7. Low carbon, energy-saving, green and reusable.

2、 Development status of steel structure industry

In recent years, China’s steel structure industry has experienced a process from slow start to rapid development. In 2016, the state issued a number of policy documents to resolve the problem of steel overcapacity and promote the green and sustainable development of the construction industry. In 2019, the Ministry of housing and urban rural development issued the “key points for 2019 work of the construction market supervision department of the Ministry of housing and urban rural development”, which required to carry out the pilot work of steel structure prefabricated housing; In July 2019, the Ministry of housing and urban rural development successively approved the pilot schemes of Shandong, Zhejiang, Henan, Jiangxi, Hunan, Sichuan, Qinghai and other seven provinces to promote the establishment of a mature steel structure prefabricated housing construction system.

Under the influence of favorable policies, market demand and other factors, the new construction area of steel structure prefabricated buildings has increased by nearly 30%. The national steel structure output also shows a steady upward trend year by year, rising from 51 million tons in 2015 to 71.2 million tons in 2018. In 2020, the steel structure output has exceeded 89 million tons, accounting for 8.36% of the crude steel,