High-strength and high-tenacity gas shielded welding wire

Abstract

The invention discloses a high-strength and high-tenacity gas shielded welding wire. The welding wire comprises the following chemical composition in percentage by mass: 0.02 to 0.12 percent of carbon (C), 1.20 to 2.10 percent of manganese (Mn), 0.20 to 1.00 percent of silicon (Si), less than or equal to 0.010 percent of sulfur (S), less than or equal to 0.015 percent of phosphorus (P), 2.00 to 3.50 percent of nickel (Ni), 0.20 to 0.80 percent of molybdenum (Mo), 0.20 to 0.30 percent of titanium (Ti), 0.60 to 1.20 percent of chromium (Cr), less than or equal to 0.05 percent of vanadium (V), 0.005 to 0.010 percent of boron (B), less than or equal to 0.015 percent of aluminum (Al), less than or equal to 0.35 percent of copper (Cu) and the balance of iron (Fe). The welding wire is used for welding steels of a strength grade of between 850 and 950MPa; and under the protection of a mixed gas (80 percent of argon (Ar) and 20 percent of carbon dioxide (CO2)), the weld metal tensile strength of the welding wire is more than or equal to 850MPa, the yield strength is more than or equal to 720MPa, the elongation is more than or equal to 22 percent, and the low-temperature impact toughness Akv is more than or equal to 181J at the temperature of -30 DEG C, or more than or equal to 175J at the temperature of -40 DEG C, or more than or equal to 162J at the temperature of -50 DEG C.

Description

technical field [0001] The invention belongs to the field of welding materials, and is a gas-shielded welding wire for metal material welding, in particular to a high-strength and high-toughness gas-shielded welding wire especially suitable for welding 850-950MPa grade high-strength and high-toughness engineering structural steel. Background technique [0002] With the continuous improvement of the strength and toughness of new steel grades for construction machinery, the steel grades used for new generation high-performance engineering structures such as construction machinery, oil pipelines, pressure vessels, cross-sea bridges, military industry warships, etc. have the characteristics of high strength and high toughness. The level has reached 850~950 Mpa. Therefore, higher requirements are put forward for the performance of welded joints. The tensile strength of weld deposited metal must reach 850~950Mpa, which is equivalent to that of the base metal, and it must also meet...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent CN1290661C introduces a high-strength and high-toughness gas shielded welding wire. The chemical composition weight percentage of the welding wire is: C: 0.04~0.12, Si: 0.40~0.80, Mn: 1.40~2.00, S:≤0.015, P: ≤ 0.020, Ni: 0.40~1.00, Cr: 0.20~0.50, Ti: 0.06~0.20, Cu: 0.30~0.50, B: 0.002~0.0079, Al: ≤0.02, the balance is Fe; weld metal low temperature impact energy -60 The ℃ is 173J, which has good low-temperature impact toughness, but the disadvantage is that the tensile strength is 735Mpa, which cannot meet the technical requirements for the matching of strength and toughness of high-strength engineering series structural steel grades of 800Mpa and above under low-temperature service

[0004] Chinese patent CN101439446A introduces a high-strength and high-toughness gas-shielded welding wire. The tensile strength of the deposited metal of this welding wire is 780~850Mpa, and the low-temperature impact toughness work is 70J at -20°C. High toughness service requirements at low temperature

The tensile strength of the deposited metal obtained by this welding wire is 800Mpa, and the impact toughness at -40°C: Akv is 100J, and the strength and toughness have been improved. However, it can be seen from the content and chemical composition of the welding wire public patent: 1. The welding wire is added with expensive Ni element (Ni: 6.8~8.0), resulting in high production cost

2. The welding wire has no restrictions on the elements S and P. It is well known that S and P are prone to hot and cold cracks in the weld. When S and P are too high, the strength and toughness of the deposited metal of the welding wire will be reduced

Images