Thick plate high-efficiency gas-slag combined protection welding method

Abstract

The invention discloses a thick plate high-efficiency gas-slag combined protection welding method. The method comprises the following steps that according to the base material performance, Rm is 450-600 MPa, and the thickness is 10-40 mm; vertical butt welding with equal thickness is carried out; two U-shaped grooves are adopted; a copper-free flux-cored wire is adopted, wherein the diameter of the copper-free flux-cored wire is 1.6 mm; protective gas is CO2 of 80% and O2 of 20%; a straight polarity method of a direct-current power supply is adopted; a current is 300-400 A, the voltage is 32-40 V, and the welding speed is 5-15 cm / min; a welding wire conductive nozzle is located in a closed space formed by the welding grooves, a welding seam front copper sliding block and a ceramic liner, and the vertical distance between the welding wire conductive nozzle and the top of the copper sliding block is 14+ / -0.1 mm; the intersection angle of the welding wire conductive nozzle and the weldingparallel line is 5-15 degrees; and during welding, a gap between the bottoms of the two U-shaped grooves is protected by the ceramic liner with an adhesive strip. According to the thick plate high-efficiency gas-slag combined protection welding method, the generation of welding stress and welding deformation can be effectively reduced, preheating is not needed before welding, heat treatment is not needed after welding, the consumption of welding materials is reduced by at least 50%, the heat input is reduced by at least 60%, and a weld joint is formed once.

Description

technical field [0001] The invention relates to a welding method of a steel plate, in particular to a gas slag joint protection welding method, and in particular to an equal-thickness butt welding method for welding steel with a welding thickness of 10 to 40 mm. Background technique [0002] In recent years, the manufacturing industries of various countries have paid more and more attention to the development of welded structures to high performance and high efficiency. With the improvement of manufacturing capacity in shipbuilding, storage tanks, large machinery and other industries, welded structures are developing towards giantization. Therefore, the application of thick plates is becoming more and more popular. As the thickness of the welded plate increases, the contradiction between welding efficiency and welding quality also emerges. At present, there are also many new welding methods to adapt to different welding scenarios, such as multi-wire submerged arc welding, ...

AI Technical Summary

Problems solved by technology

Such welding grooves and angles not only increase the consumption and energy consumption of welding materials, but also easily cause welding deformation and unsafe hidden dangers in welding applications, especially for thick plate welding, which will increase the unsafety of the entire welding structure

[0008] From the results of the above documents, the gas-electric vertical welding method adopted in the prior art, due to the restrictive one-time forming of the weld seam, has a larger welding groove and requires more welding materials; and the front and back of the weld seam are both Cooling sliders or pads are required to form, and the assembly requirements before welding are high and cumbersome, resulting in a decrease in welding speed and an increase in heat input, which can easily cause coarse grains in the weld, resulting in a decrease in weld performance, welding deformation, and increased welding stress, exacerbating the structural safety risk of the entire welded joint

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