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Steel structure Materials is a structure composed of steel materials, which is one of the main types of building structures.
Steel Structure Materials has been reasonably and widely used in the field of construction engineering all over the world, especially in developed countries and regions.
The steel structure industry is usually divided into five sub categories: light steel structure, high-rise steel structure, residential steel structure, space steel structure and bridge steel structure.
The Steel Structure Materials is mainly composed of beam steel, steel column, steel truss and other components made of section steel and steel plate, and adopts rust removal and rust prevention processes such as silylation, pure manganese phosphating, water washing and drying, galvanizing and so on.
Steel structures are mainly used in bridges, buildings, lighthouses, ships and other fields.
In addition to steel structure, there are wood structure, concrete structure, brick concrete structure and other structures.
The strength index of steel is determined by elastic limit σ e. Yield limit σ y. And tensile limit σ u. The design is based on the yield strength of steel.
High yield strength can reduce the self weight of the structure, save steel and reduce the cost. tensile strength σ U is the maximum stress that the steel can bear before failure.
At this time, the structure loses its service performance due to large plastic deformation,
but the structural deformation is large and does not collapse, which meets the requirements of the structure to resist rare earthquake‘ σ u/ σ The value of y can be regarded as the parameter of steel strength reserve.
The plasticity of steel generally means that after the stress exceeds the yield point, it has the property of significant plastic deformation without fracture.
The main index to measure the plastic deformation capacity of steel is elongation δ And reduction of area ψ。
The cold bending performance of steel is to measure the resistance of steel to cracks when plastic deformation occurs during bending at room temperature.
The cold bending performance of steel is to test the bending deformation performance of steel under the specified bending degree by cold bending experiment.
The impact toughness of steel refers to the ability of steel to absorb mechanical kinetic energy in the fracture process under impact load.
It is a mechanical property to measure the resistance of steel to impact load cutting, which may lead to brittle fracture due to low temperature and stress concentration.
Generally, the impact toughness index of steel is obtained through the impact test of standard specimens.
The welding performance of steel refers to the welding joint with good performance under certain welding process conditions.
Welding performance can be divided into welding performance in welding process and welding performance in service performance.
The welding performance in the welding process refers to the sensitivity that the weld and the metal near the weld do not produce thermal cracks or cooling shrinkage cracks during cooling.
Good welding performance means that there is no crack in the weld metal and nearby base metal under certain welding process conditions.
The welding performance in service performance refers to the impact toughness at the weld and the ductility in the heat affected zone.
It is required that the mechanical properties of the weld and the steel in the heat affected zone shall not be lower than those of the base metal.
China adopts the welding performance test method of welding process and the welding performance test method of usability.
