A572 Gr50 grade hot rolled equal unequal steel angle for bridge construction and ships

ASTM A572 Gr50 hot rolled unequal angle steel is made of high strength low alloy niobium-vanadium structural steel with a yield strength of ≥345MPa, a tensile strength of 450-600MPa, and an elongation of ≥18%. It is suitable for load-bearing structures such as bridge truss node plates and ship deck supports. Its chemical composition contains C≤0.23%, Mn≤1.35%, and Nb (0.005-0.05%) and V (0.01-0.15%) are added. The impact toughness at -20℃ is increased to ≥27J through fine grain strengthening to meet dynamic load requirements.

A572 Gr50 angle steel is hot rolled, with common specifications such as L150×100×10mm. The flange thickness difference design optimizes stress distribution and reduces weight by more than 15% compared to equilateral angle steel. Its carbon equivalent CEIIW≤0.45%, supports submerged arc welding and gas shielded welding, and the welding preheating temperature needs to be ≥10℃ (rising to 120-150℃ when the plate thickness is ＞25mm).

In shipbuilding, A572 Gr50 unequal angle steel is used to connect the side longitudinals and bulkheads, and its seawater corrosion resistance is better than A36 steel; in the bridge field, it is mostly used in suspension bridge anchoring systems, and its fatigue life is 30% higher than that of Q355B. The surface can be sandblasted or hot-dip galvanized, and the salt spray test is ≥500 hours.