High-linear-energy submerged-arc welding method for bridge steel with yield strength higher than or equal to 500MPa

Abstract

The invention discloses a high-linear-energy submerged-arc welding method for bridge steel with the yield strength higher than or equal to 500MPa. The high-linear-energy submerged-arc welding method includes that properties of an applicable base plate includes that the yield strength R<eL> is higher than or equal to 500MPa, the tensile strength R<m> is higher than or equal to 650MPa, the elongation is higher than or equal to 18%, and impact energy KV<2> at the temperature of -40 DEG C is higher than or equal to 120J; plate thickness combinations have equal thicknesses of 32mm; welding grooves are double-faced U-shaped symmetric grooves, an angle of each groove is 60 degrees, and the dimensions of each truncated edge is 6mm and R6mm; the tensile strength of each matched welding wire is higher than or equal to 650MP, and the diameter of each matched welding wire is phi4.0mm; a welding current ranges from 700A to 750A, a welding voltage is 32V, a welding speed ranges from 30cm / min to 26cm / min, welding linear energy ranges from 45kJ / cm to 55kJ / cm, and flux is baked at the temperature of 350 DEG C for 1 hour; multilayer multiple continuous welding procedures are implemented. The high-linear-energy submerged-arc welding method has the advantages that requirements on high-linear-energy submerged-arc welding for medium-thickness plate structures in construction for large-span road and highway dual-purpose bridges with the span larger than 1000 meters can be met, the tensile strength R<m> of each butt joint welding seam is not lower than 690MPa, joint cold bending d is 3a at the angle of 180 degrees and is qualified, impact energy KV<2> of each welding seam at the temperature of -40 DEG C is not lower than 134J, impact energy KV<2> of each weld line at the temperature of -40 DEG C is not lower than 95J, and impact energy KV<2> of a heat-affected zone (with the size of 1mm) at the temperature of -40 DEG C is not lower than 72J; three zones of the joints are high in impact toughness capacity and safety margin, preheating is omitted before welding, and heat treatment is omitted after welding.

Description

technical field [0001] The invention relates to a large-span energy submerged arc welding method, which belongs to the large-span energy submerged arc welding process of high-strength bridge thick plate structural steel, and is suitable for large-span bridge steel with yield strength ≥ 500 MPa and tensile strength R m ≥650MPa, Elongation A≥18%, -40 o CKV 2 Submerged arc welding method for bridge thick plates with impact energy ≥ 120J. Background technique [0002] With the development of economic construction, the development of the transportation industry is also an important aspect, and it is even an industry that must be developed first. For example, my country's bridge construction is advancing by leaps and bounds, constantly developing towards high strength, large span, heavy load, and high speed. For example, it is planned to build a long-span public and railway bridge with 6-line highway and 4-line railway in the Yangtze River Bridge, and the span of the main bridg...

AI Technical Summary

Problems solved by technology

Its shortcomings: low strength level, and preheating process at 80~100°C before welding. The preheating process not only wastes energy, but also has low production efficiency.

At present, the measures to prevent cracks in the large-scale steel structure manufacturing process must be preheated before welding and heat treated after welding, which means that the construction environment, manufacturing cost and manufacturing cycle are difficult.

Images