Q345B steel details

Q345B is a low-alloy high-strength structural steel, widely used in China's engineering field, is one of the Q345 series of steel. The "Q" in its name represents the yield point, the "345" refers to its minimum yield strength of 345 MPa, and the "B" represents the quality grade, which has excellent mechanical properties and processing properties. Compared with Q235B, Q345B has higher strength and is suitable for building structures, Bridges, pressure vessels, machinery manufacturing and other fields under large loads, while maintaining good toughness and welding performance.

Q345B has a variety of sizes and specifications, and can be made into steel plates, sections (such as H-beams, I-beams), steel pipes and other forms. The thickness of the steel plate generally varies from 2 mm to several hundred mm, and the section size of the section steel and steel pipe is designed according to the specific use to meet the different engineering needs. Its chemical composition mainly includes carbon (C≤0.20%), silicon (Si≤0.55%), manganese (Mn≤1.70%), sulfur (S≤0.035%), phosphorus (P≤0.035%), and may trace to add niobium (Nb), vanadium (V) or titanium (Ti) and other alloying elements to improve strength and durability.

The Q345B is usually delivered in a hot-rolled or normalized state, which is suitable for most conventional uses, while normalizing further improves its internal organization and improves toughness and uniformity. Surface treatment can be sandblasted, galvanized or coated on demand to enhance corrosion resistance. Q345B is known for its high cost performance in practical applications, especially in engineering projects that need to balance strength and economy, and has become one of the indispensable materials in modern industry and construction.