800MPa-grade high-strength high-tenacity gas shielded welding wire

Abstract

The invention provides a 800MPa-grade high-strength high-tenacity gas shielded welding wire which is suitable for welding engineering machinery, coal mine machinery, railroad bridges, hydropower industry, delivery lines and high-pressure containers. The gas metal arc welding wire contains the chemical compositions in weight percent: 0.05-0.10 percent of C, 0.20-0.60 percent of Si, 1.60-2.10 percent of Mn, 1.8-2.4 percent of Ni, 0.2-0.6 percent of Mo, 0.10-0.50 percent of Cr, 0.04-0.10 percent of Ti, 0.02-0.08 percent of Zr, not more than 0.010 percent of S, not more than 0.015 percent of P and the balance of Fe and unavoidable impurities. Since the Ar+20% CO2 argon-rich gas shielded welding is adopted by the welding wire, low-alloy high-strength steel the tensile strength Rm of which is not lower than 800MPa can be welded; under the as welded and postwelding thermal refining condition, weld metal has high strength and good low-temperature impact toughness.

Description

technical field [0001] The invention belongs to the field of welding materials, specifically a Ti and Zr microalloyed high-strength and high-toughness gas-shielded welding wire, which uses Ar+20% CO 2 Argon-rich gas shielding can weld low-alloy high-strength structural steel with a strength level greater than 800MPa. Background technique [0002] With the advancement of smelting technology and the application of controlled rolling, controlled cooling and microalloying elements, the performance of steel is developing towards high strength and high toughness, so as to reduce material consumption, reduce structural weight, and improve structural performance and safety. . This will put forward higher requirements on the strength and toughness of the welded joint, and then on the welding material and welding process. In recent years, 800MPa high-strength structural steel has been used in hydraulic supports of coal mining machinery, coupler frames of locomotives, transportation ...

AI Technical Summary

Problems solved by technology

Although these two kinds of welding wires can meet the strength requirements of the weld metal, because the welding wire invented by patent CN1709635A contains 0.1-0.55% Cu, the welding wire invented by patent CN1654160A contains 0.01-0.05% Nb, and Cu and Nb elements belong to precipitation Strengthening elements, which will precipitate out during post-weld heat treatment, resulting in hot embrittlement

In addition, these two invention welding wires both contain trace element B, which is easily segregated during the smelting process, resulting in uneven chemical composition and unstable toughness of the weld metal