ASTM A572 grade 50 high strength steel wide flange H beam

ASTM A572 grade 50 wide flange H beam is a high strength low alloy niobium vanadium structural steel with a yield strength of ≥345MPa (50ksi), a tensile strength of 450-600MPa, and an elongation of ≥18%. It is suitable for heavy-load scenarios such as high-rise building steel beams and bridge main structures. Its carbon content is ≤0.23%, and 0.005-0.05% niobium (Nb) and 0.01-0.15% vanadium (V) are added as microalloying elements to improve comprehensive performance through fine grain strengthening and precipitation strengthening.

A572 grade 50 steel is produced by hot rolling process, and the thickness ratio of flange to web is optimized. For example, the flange width of W16×36 specification is 177.5mm, the web thickness is 7.5mm, and the section moment of inertia is 448in⁴, which can achieve large-span lightweight design. Compared with ASTM A36 steel, its strength is increased by more than 40%, and the welding carbon equivalent (CEIIW) is ≤0.45%, which is suitable for bolt connection or welding construction.

In engineering applications, ASTM A572 grade 50 H shaped steel has similar performance to the national standard Q355D and European standard S355JR, and is widely used in North American steel structure buildings and export projects, especially for dynamic load structures such as crane main arms and mining machinery frames. Its thickness covers 8-300mm, and its low-temperature toughness can be further improved through normalizing heat treatment.