Three-wire submerged-arc welding method for thick plate, low alloy, high strength steel

Abstract

A three-wire hidden arc welding method for the thick plate of low-alloy high-strength steel features that three welding wires are longitudinally arranged in such manner that one is connected to positive electrode of DC power supply and another two to AC power supply to form a fusion pool, the gap between adjacent two welding wires is 10-15 mm and the included angle between welding wire and workpiece is respectively 90-105 deg, 90-105 deg, and 60-80 deg.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a three-wire submerged arc welding method for thick plate low alloy high strength steel. Background technique [0002] At present, the welding of domestic low-alloy high-strength steel (Q345 steel and above steel grades) is limited to twin-wire or single-wire submerged arc welding, and when welding joints with mechanical performance requirements, double-wire submerged arc welding is used. , the welding specification must be limited within a narrow range (the welding current generally cannot exceed 650A, and the welding line energy is limited below 45KJ / cm), otherwise, it is difficult to balance the mechanical properties and operational weldability of the joint, which greatly limits the multi-wire welding performance. Advantages of submerged arc welding technology. [0003] In the 21st century, super high-rise, long-span world-class large-scale steel structure buildings have spr...

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Problems solved by technology

[0002] At present, the welding of domestic low-alloy high-strength steel (Q345 steel and above steel grades) is limited to twin-wire or single-wire submerged arc welding, and when welding joints with mechanical performance requirements, double-wire submerged arc welding is used. , the welding specification must be limited within a narrow range (the welding current generally cannot exceed 650A, and the welding line energy is limited below 45KJ / cm), otherwise, it is difficult to balance the mechanical properties and operational weldability of the joint, which greatly limits the multi-wire welding performance. The Advantages of Submerged Arc Welding Technology

[0003] In the 21st century, super high-rise, long-span world-class large-scale steel structure buildings have sprung up one after another in my country's construction industry. In order to reduce structural weight, reduce manufacturing costs and improve structural reliability, a large number of high-strength and high-toughness thick plates Building structural steel is widely used, so the traditional single-wire submerged arc welding method is extremely difficult to meet the high-efficiency and high-quality welding requirements of this type of building structure

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