Industry Structural Steel Plate

Dec 2, 2013

R & D Direction of Construction Industry Structural Steel Plate

Over the years, construction industry has been in use for common structural steel - carbon steel and low alloy steel, the steel strength performance requirements, the yield strength in 460MPa. As a result of the welding process, the steel has good weldability and require a certain degree of ductility and toughness to ensure that the requirements of construction and the prevention of brittle fracture. In just a few years, the rapid rise of steel structure, become the vanguard of steel construction industry. However, in recent years, the construction industry is the development trend of heavy-duty, high-rise, large span and space asymmetric structure, construction conditions and use of the environment should take into account more demanding, so the steel plate put forward new requirements, and general steel building structural steel from a specially developed high - performance special steel. Behind the brilliant achievement, obtained the national, provincial, municipal leaders at all levels of care and support. These performance requirements are below:

1. High strength. Yield strength level will be widely used 345MPa steels generally increased to more than 400MPa.

2. Lamellar tearing resistance. Construction steel plate thickness direction performance is a type of steel items will be seized. The measures taken is the sulfur content in the steel reduced to 0.01 to 0.005%, and to control the morphology of inclusions. With the ultra-high-rise, large span building structures used at the beam-column joints thickness greater than 50mm special plate lamellar tearing resistance performance requirements along the thickness direction of the tensile test section shrinkage of 25 to 35%.

3. Earthquake resistance. Seismic design to steel to absorb seismic energy yield to the greatest degree of plastic deformation, to ensure that the performance of the seismic safety of buildings. Therefore, the required use steel with low yield ratio, and strict control of the yield point of the fluctuation range. Building structure with steel standard provisions of the new formulation of the yield ratio is not greater than 0.83, the yield strength fluctuation range of 110MPa.

4. To improve the weldability. Improve weldability first and foremost is to reduce the cold cracking susceptibility, measures to reduce the the welded carbon equivalent and the welding crack sensitivity index. In addition, the implementation of high-efficiency requirements for welding materials able to withstand welding up to 100kJ/cm line energy.

5. Refractory heat-resistant. The building structure with the requirements of the refractory steel is heated to 600 ℃, the yield strength can be maintained at more than 2/3 of the value of room temperature. According to the results of existing studies, Mo Nb composite steels more suitable.