Coated welding wire for welding low-alloy high-strength steel and manufacturing method

Abstract

The invention discloses a coated welding wire for welding low-alloy high-strength steel. The coated welding wire comprises a welding wire substrate and a coating which coats the surface of the welding wire substrate, wherein the welding wire substrate is made from the following components in percentage by weight: 0.029 to 0.041 percent of Ti, 0.01 to 0.015 percent of Al, 0.083 to 0.11 percent of Nb, 0.1 to 0.15 percent of C, 0.2 to 0.3 percent of Cr, 0.3 to 0.5 percent of Si, 0.01 to 0.03 percent of N, 1.4 to 1.7 percent of Ni, 0.1 to 0.6 percent of Mo, less than or equal to 0.002 percent of P, less than or equal to 0.002 percent of S, and the balance of iron and unavoidable impurities, wherein as specified by the following formula, K is between 0.013 and 0.032, K=29[Ti]+52[Al]+27[Nb]-100[N]; [Al], [Ti], [Nb] and [N] represent the weight percentage contents of Al, Ti, Nb and N in the welding wire substrate respectively. The invention further discloses a manufacturing method of the coated welding wire for welding the low-alloy high-strength steel. By adopting the coated welding wire, high strength of welding metal is ensured, the welding performance of the low-alloy high-strength welding wire is improved finitely, the occurrence of cold cracks is controlled, a low splashing rate is achieved, and the welding requirement of the high-strength low-alloy steel is met.

Description

technical field [0001] The invention relates to the technical field of coated welding wire, in particular to a coated welding wire for welding low-alloy high-strength steel and a preparation method thereof. Background technique [0002] Low-alloy high-strength steel has good weldability, excellent formability and low manufacturing cost, so it is widely used in pressure vessels, vehicles, bridges, construction, construction machinery, mining machinery, textile machinery, marine structures and other fields. With the development of modern industry, the welding structure tends to be large-scale, large-capacity and high-parameter. Many new problems have emerged in the production of welded low-alloy high-strength steel, among which the most common and serious one is welding. crack. Common welding cracks can be divided into hot cracks, cold cracks and reheat cracks according to the temperature at which they are generated. Cold cracks are most likely to occur in welding low-medium...

AI Technical Summary

Problems solved by technology

Delayed cracks have three processes: incubation period, slow diffusion period and sudden fracture period, which seriously affect the mechanical properties of welded products and cause serious losses to industrial production

In order to prevent the occurrence of cold cracks, basic welding rods or fluxes are often used, but because basic welding rods cannot meet the strength requirements of low-alloy steels, it is necessary to explore a method that is suitable for the welding performance of low-alloy high-strength steels and can effectively prevent cold cracks. Welding wire, so as to obtain low-alloy high-strength steel products with better performance, has become a technical problem that those skilled in the art need to solve urgently

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