Development trend of steel for steel structure

Development trend of steel for building steel structure in China

The steel used in building structure mainly refers to the thick plate, thin plate (4 ~ 6mm ordinary plate), galvanized coil, small and medium-sized steel (work, groove, Angle steel), hot rolled H-shaped steel, welded pipe (straight seam pipe and spiral pipe) and cold formed (C steel, Z steel, rectangular pipe, main pipe, etc.). According to the development of steel structure application technology in recent years, these varieties show four major development trends in application:

(1) Medium and thick plate has become the leading variety of application

First of all, because for a long time, the application of steel structure has formed a basic pattern with welded composite members as the main bearing structure; Secondly, the price of steel plate in the profile is lower, and the flexibility, adaptability and economy of the plate combination are stronger, and there is less need for substitution.

(2) The supply and demand of economic profiles such as hot-rolled H-shaped steel and cold-formed thin-wall steel will increase

Steel sandwich

Compared with the traditional random shaped profiles (I-beams, channel steel), hot-tied H-beams and cold-formed steel have obvious sectional properties and significant economic benefits. At present, with the implementation of policies and conditions to promote the use of economic profiles is increasing, and will continue to increase.

The amount of large and medium-sized Angle steel is reduced

Due to the rapid development of lightweight and lightweight steel structure, the application of grid frame and light portal steel frame is more extensive, so the amount of large and medium-sized Angle steel used in the traditional heavy roof has been significantly reduced. In particular, large Angle steel (side length greater than or equal to 180mm) is relatively expensive and is now rarely used.

The application of hot rolled I-beam and channel steel also showed a decreasing trend

Hot-rolled I-beam and channel steel have no obvious advantages in cross section characteristics and high price, when the specifications are selected for a little longer, the supply is not guaranteed, so the amount of heavy floor, bracket, frame, etc. in its main areas is also decreasing, and has been replaced by hot-rolled or welded H-beam steel trend. From the point of view of material and material, the various types of steel of Q235 and Q345 steel supplied on the market at present can ensure the basic needs of building steel structures, especially according to the revised "carbon structural steel" (GB700-2006), "Low alloy high strength structural steel" (GB1591-94) and other standards of supply steel, with a scientific quality grade. Moreover, the thickness range is expanded, the product quality can be ensured more effectively and in line with international standards, and the design and application are more convenient. From the perspective of product varieties and lattice, the varieties of domestic steel in China also basically meet the needs of the development and application of the current building steel structure, showing a trend of accelerating the development of steel for steel structure.