Q345B Carbon steel pipe is a low-alloy high-strength structural steel pipe that implements the Chinese standard GB/T 8163 or GB/T 1591. In its name, "Q" represents yield strength, "345" means that the yield strength is not less than 345MPa, and "B" represents the quality grade, which guarantees the low-temperature impact toughness of -20℃.

By adding appropriate amounts of alloy elements such as manganese and silicon, this material significantly improves the strength while maintaining good plasticity and weldability. It is an upgraded alternative product for ordinary carbon steel.

This type of steel pipe can be divided into seamless pipes and welded pipes according to the process, and is widely used in building steel structures, bridge engineering, mechanical equipment, pressure vessels and other fields. Its outstanding feature is high cost performance. It can not only meet the strength requirements of general structural parts, but also has excellent processing performance, and supports cutting, bending, welding and other forming processes.

Common specifications cover diameters from 10mm to 2000mm and wall thicknesses from 1mm to 50mm. Different sizes and process forms can be selected according to engineering needs. When used in open air or low temperature conditions, Q345B has more reliable safety performance than ordinary carbon steel (Q235).