The invention discloses a gas-shielded
welding method for high-strength bridge steel, which comprises the following steps: (1) the high-strength bridge steel with the tensile strength of between 570 and 650MPa and the thickness of 50 millimeters is adopted, a matched
welding material is adopted, wherein the tensile strength of a
welding wire is between 570 and 660MPa, and the
diameter of the welding wire is 1.2 millimeters; (2) a gas-shielded welding groove adopts a double V-shaped symmetrical groove, the angle of the groove is 60 DEG, and the truncated edge is 2 millimeters; (3) the
welding process specification is as follows: the welding current is between 250 and 270 amperes, the welding
voltage is between 23 and 27 volts, the welding speed is between 30 and 29 centmeters / minute, the welding heat input is between 12 and 15kJ / cm, the
argon-rich
mixed gas metal arc welding with 20 percent of CO2 and 80 percent of Ar is adopted, the flow of gas is between 18 and 20 liters / minute, no preheating is performed before welding, and no heat treatment is performed after the welding; and (4) the gas-shielded welding adopts multi-layer multi-passage continuous welding, and the interlayer temperature is controlled to between 100 and 150 DEG C. The welding method has the advantages of good welding
processing property, simple and convenient operation, applicability, convenience, high efficiency, and
energy conservation, and is applicable to the manufacturing, promotion and application of large-span bridge steel of factories.