A high-strength and high-toughness gas shielded welding wire

Abstract

The invention relates to a high-strength and high-toughness gas shielded welding wire, which is suitable for welding 800MPa-level high-strength steel. Its chemical composition (by weight %) is: C 0.02-0.05; Si0.30-0.80; Mn 2.0-2.50; P<0.010; S<0.010; Cr 0.70-1.2; Mo 0.70-1.2; Ti 0.02-0.12; B 0.003-0.005; Ni 2.0-3.2; RE 0.05-0.1; Nb 0.01-0.06; the balance is Fe and unavoidable impurities. The welding wire of the invention has the characteristics of simple composition design, economy, good manufacturability, etc., and the welding seam metal has high strength and toughness, and is suitable for welding at positions requiring high low-temperature toughness. After experiments, the welding wire is used to weld the weld metal Rm≥800MPa, ReL>760MPa; the impact energy of the weld metal at -50°C is AkV≥37J.

Description

technical field [0001] The invention relates to a high-strength and high-toughness gas-shielded welding wire, which belongs to the field of matching welding materials for high-strength steel, and is particularly suitable for gas-shielded welding of 800MPa high-strength steel. Background technique [0002] With the rapid development of my country's industry, the strength level of steel materials is gradually developing in the direction of high strength and high toughness. Construction machinery, hydropower and water conservancy, petrochemical and other industries have begun to use a large number of steel grades with a strength level of 800Mpa. However, the research and development of welding materials for this ultra-high-strength steel in China is still lagging behind, and the existing welding wires are less than equal. Even if a small amount of successfully developed welding wire is not costly and requires heat treatment after welding, the low-temperature impact toughness a...

AI Technical Summary

Problems solved by technology

Construction machinery, hydropower and water conservancy, petrochemical and other industries have begun to use a large number of steel grades with a strength level of 800Mpa. However, the research and development of welding materials for this ultra-high-strength steel in China is still lagging behind, and the existing welding wires are less than equal. Even if a small amount of successfully developed welding wire is not costly and requires heat treatment after welding, the low-temperature impact toughness and manufacturability of the weld metal cannot meet the requirements. In addition, the content of Mo and Ni in the currently developed welding wire is very high. Moreover, preheating is required during the welding process, which greatly increases the cost and welding difficulty of the welding wire. Therefore, it is very urgent to develop a gas-shielded welding wire with high strength, high toughness and good manufacturability.