GB/T 4171
GB/T 4171 is a Chinese national standard (where GB/T stands for "National Recommended Standard") specifying technical requirements for weathering structural steel. It covers hot-rolled and cold-rolled steel plates, strips, and sections with atmospheric corrosion resistance and good weldability, suitable for vehicles, bridges, containers, buildings, towers, and other structures. Weathering structural steel under the GB/T 4171 standard enhances atmospheric corrosion resistance by adding small amounts of alloying elements such as Cu, P, Cr, and Ni. These elements work synergistically to form a stable protective film on the surface of the steel, providing corrosion resistance 2–8 times that of ordinary carbon steel. This significantly reduces maintenance costs, minimizes the need for anti-corrosion coatings, extends the service life of structures, and aligns with the concept of green and low-carbon development.
Q550NH steel plate is a top-grade weathering steel for welding specified in the GB/T 4171 standard. It combines high strength (with a yield strength ≥550 MPa), excellent weather resistance (4 to 6 times that of ordinary steel), and good weldability. This makes it particularly suitable for ...
GB/T 4171 Q500NH is a high-quality weldable structural steel that combines high strength (yield strength ≥ 500 MPa) with excellent weather resistance. It is especially suitable for large-scale engineering structures that are exposed to the atmosphere for long periods and difficult to maint...
GB/T 4171 Q460NH is a weldable specialized structural steel that combines both high strength and excellent atmospheric corrosion resistance. During its design and selection, the specific quality grade (A/B/C/D/E) must be clearly defined. Particular attention should be paid to its welding p...
GB/T 4171 Q415NH is a high-strength low-alloy structural steel that combines high strength, excellent weathering resistance, and good welding performance. It is particularly suitable for large-scale engineering structures exposed to atmospheric environments for extended periods. It can sig...
GB/T 4171 Q355NH is a high-weathering structural steel compliant with Chinese national standards, characterized by a yield strength of ≥355 MPa and excellent atmospheric corrosion resistance. It is suitable for constructing modern outdoor steel structures that require no painting, low main...
GB/T 4171 Q355GNH is a high-performance structural steel with a yield strength of 355 MPa, high weather resistance, and suitability for welding. It is primarily used in various engineering structures that require long-term exposure to the atmosphere and possess atmospheric corrosion resist...
