Structure Steel mainly used for Heavy steel structure, Light steel structure, Equipment steel structure, can be subdivided into: Carbon Structural Steel (Carbon Steel Beam and Column), high-quality carbon structural steel (High Strength Steel Structure), High Strength Low Alloy (HSLA) Structural Steel Beam and Column), alloy structural steel (Ultra-high load-bearing steel structure, spring steel, weathering structural steel, chip-free structural steel, non-quenched and tempered mechanical structural steel) etc.

Steel structure is a structure composed of steel materials and is one of the main types of building structures which meet specific strength and formability grades, mainly in shapes of H beam, Channel, Angle, Pipe & Tube.  The structure is mainly composed of steel beams, steel columns, steel trusses and other components made of section steel and steel plates, and adopts rust removal and rust prevention processes such as silanization, pure manganese phosphating, washing and drying, and galvanizing. Welds, bolts or rivets are usually used to connect components or parts. Because of its light weight and simple construction, it is widely used in large workshops, venues, super high-rises and other fields. The steel structure is easy to rust. Generally, the steel structure needs to be derusted, galvanized or painted, and it needs to be regularly maintained.

Steel grade classification:
There are many kinds of steel, and only a few meet the requirements of steel structure, such as Q235 in carbon steel, l6Mn in low alloy steel, 20 manganese vanadium steel (20MnV) for high strength bolts, etc. The structural steel standards and grades of various countries are as follows:

European Standard Non-alloy Structural Steel Grade :
S235JR, S235J0, S235J2
S275JR, S275J0, S275J2
S355JR, S355J0, S355J2, S355K2
SS460JR, S460J0, S4600J2, S460K2
S500J0

European Standard Weldable Fine Grain Structural Steel Grade :
S275M, S275ML
S355M, S355ML
S420M, S420ML
S460M, S460ML
S500M, S500ML

American Standard Structural Steel Grades :
A36-14 Grade 36
A572-18 Grade 42, 50, 55, 60, 65
A588-19 Grade B
A709-18 Grade 36, 50, 50S, 80
A913-19 Grade 50, 65, 70, A992-11(15) Grade 50

Russian Standard Structural Steel Grades :
GOST 27772-2015 – C255, C345, C355
GOST 19281-2014 09G2S

Chinese Standard Structural Steel Grades :
GB/T 33968 – 2017 Q345QST, Q420QSR, Q460QST, Q485QST

Features of steel structure
1. High material strength and light weight
Steel has high strength and high modulus of elasticity. Compared with concrete and wood, the ratio of its density to yield strength is relatively low, so under the same stress conditions, the steel structure has a small cross-section and light weight, which is convenient for transportation and installation, and is suitable for large spans, high heights, and heavy loads Structure.
2. Steel toughness, good plasticity, uniform material and high structural reliability
It is suitable for bearing shock and dynamic load, and has good seismic performance. The internal structure of steel is uniform, close to isotropic homogeneous body. The actual working performance of the steel structure is more in line with the calculation theory. Therefore, the reliability of the steel structure is high.
3. High degree of mechanization of steel structure manufacturing and installation
Steel structural members are easy to manufacture in factories and assemble on site. The factory mechanized manufacturing of steel structural components has high precision, high production efficiency, fast assembly speed on site, and short construction period. Steel structure is the most industrialized structure.
4. Good sealing performance of steel structure
Because the welded structure can be completely sealed, it can be made into high-pressure containers, large oil pools, pressure pipes, etc. with good air tightness and water tightness.
5. Steel structure is heat-resistant and not fire-resistant
When the temperature is below 150 °C, the properties of the steel change little. Therefore, the steel structure is suitable for hot workshops, but when the surface of the structure is exposed to heat radiation of about 150 ° C, it should be protected by a heat insulation board. When the temperature is between 300°C and 400°C, the strength and elastic modulus of the steel decrease significantly. When the temperature is around 600°C, the strength of the steel tends to zero. In buildings with special fire protection requirements, the steel structure must be protected by refractory materials to improve the fire resistance rating.
6. Poor corrosion resistance of steel structure
Especially in the environment of wet and corrosive media, it is easy to rust. Generally, the steel structure needs to be derusted, galvanized or painted, and it needs to be maintained regularly. For the structure of the offshore platform in seawater, special measures such as “zinc block anode protection” should be adopted to prevent corrosion.
7. Low carbon, energy saving, green and environmental protection, reusable
The demolition of steel structure buildings hardly produces construction waste, and the steel can be recycled and reused.

Material requirements
The steel structure will be subjected to various forms of action (load, uneven settlement of the foundation, temperature, etc.) during use, so it is required that the steel should have good mechanical properties (strength, plasticity, toughness) and processing properties (cold and hot working and welding) performance) to ensure the safety and reliability of the structure.

Performance
1. Strength
The strength index of steel is composed of elastic limit σe, yield limit σy, and tensile limit σu. 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 construction costs. The tensile strength σu is the maximum stress that the steel can withstand before it is damaged. 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 earthquakes. The value of ‘σu/σy can be regarded as a parameter of steel strength reserve.
2. Plasticity
The plasticity of steel generally refers to the property of significant plastic deformation without fracture after the stress exceeds the yield point. The main indicators to measure the plastic deformation ability of steel are elongation δ and area shrinkage ψ.
3. Cold bending performance
The cold bending performance of steel is a measure of the resistance of steel to cracks when plastic deformation occurs during bending at room temperature. The cold bending performance of steel is to use the cold bending test to test the bending deformation performance of the steel under the specified bending degree.
4. Impact toughness
The impact toughness of steel refers to the ability of steel to absorb mechanical kinetic energy during the fracture process under impact load. The impact toughness index of steel is generally obtained through the impact test of standard specimens.
5. Welding performance
The welding performance of steel refers to obtaining a welded joint with good performance under certain welding process conditions. Welding performance can be divided into welding performance in welding process and welding performance in use performance. Welding performance during welding refers to the sensitivity that the weld and the metal near the weld do not produce hot cracks or cooling shrinkage cracks during the welding process. Good welding performance means that under certain welding process conditions, neither the weld metal nor the nearby base metal cracks. The welding performance in terms of 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 are not lower than the mechanical properties of the base metal. In my country, the welding performance test method of the welding process is adopted, and the welding performance test method of the usable nature is also adopted.
6. Durability
There are many factors that affect the durability of steel. First of all, the corrosion resistance of steel is poor, and protective measures must be taken to prevent the steel from corroding and rusting. The protective measures include: regular maintenance of the steel paint, the use of galvanized steel, and special protective measures in the presence of strong corrosive media such as acid, alkali, salt, etc. A zinc ingot is fixed on the jacket, and the seawater electrolyte will automatically corrode the zinc ingot first, thus achieving the function of protecting the steel jacket. Secondly, because the failure strength of steel under high temperature and long-term load is much lower than that of short-term strength, the permanent strength of steel under long-term high temperature should be measured. Steel will automatically harden and become brittle over time, a phenomenon known as “aging”. The impact toughness of steel under low temperature load should be tested.

General Product range