Submerged arc composite welding method of bridge steel thick plate with tensile strength greater than or equal to 810MPa

Abstract

The invention discloses a submerged arc composite welding method of a bridge steel thick plate with the tensile strength greater than or equal to 810MPa. The submerged arc composite welding method comprises the steps that according to the mechanical properties of a substrate, ReL is greater than or equal to 690 MPa, Rm is greater than or equal to 810MPa, A is greater than or equal to 14%, and -40DEG C KV2 ballistic work is greater than or equal to 120J; 32mm and 50mm equal thickness bridge steel welding is performed; a groove is a double-sided V-shaped symmetrical groove, the angle of the groove is 60 degrees, and the truncated edge is 1mm; welding wires comprising a welding wire for submerged-arc welding and a gas-shielded welding wire are selected; and welding process is performed, specifically, gas shielded arc welding backing is firstly performed, and then capping is subjected to submerged-arc welding. According to joint performance, Rm of a weld joint is greater than or equal to810MPa, the joint cold bending d is 3a, the qualified angle is 180 degrees, the weld joint ballistic work -40 DEG C KV2 is greater than or equal to 100J, fusion line ballistic work -40 DEG C KV2 is greater than or equal to 106J, heat affected zone (1mm) -40 DEG C KV2 is greater than or equal to 160J, the average impact work of weld joint three areas is much higher than a standard value, the corrosion resistance index I value of the weld joint is greater than or equal to 8.78. The weld joint three areas have high impact toughness reserve and safety margin.

Description

technical field [0001] The invention relates to a welding method for large-span bridge steel thick plates, specifically belonging to a submerged arc composite welding method for bridge steel thick plates with a tensile strength ≥ 810 MPa, which is suitable for welding tensile strength R m Welding of steel 50mm, 32mm and other thick plate joints for ≥810MPa high-strength bridge structures. Background technique [0002] With the substantial improvement of my country's railway and highway transportation capacity, the construction scale of railway and highway bridges continues to expand, and the technical level continues to improve. The function, structure and construction technology of bridges are adapting to high speed, heavy load, large span, and good integrity. , high safety, and adopt the direction of steel structure with all-welded joints. Therefore, the requirements for strength, low temperature toughness, corrosion and other performance and welding performance of bridge ...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to solve the deficiencies in the prior art, and propose a bridge steel thick plate submerged arc composite welding method with a tensile strength ≥ 810 MPa to solve the problem of two-way 8-lane, and the main bridge adopts a heavy-duty road bridge joint with a span of 408 meters There is no preheating before welding and no heat treatment after welding. Under the premise of ensuring safe service, the structure after welding will not be deformed or cracked, and the joints have excellent comprehensive mechanical properties and weather resistance.

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