700MPa low-alloy high-strength welding wire for heavy machinery and use method thereof

Abstract

The invention provides a low-alloy high-strength welding wire suitable for heavy machinery. The low-alloy high-strength welding wire is characterized in that the strength of a deposited metal is more than 700MPa, the elongation is greater than 16% and the impact energy is more than 47J at minus 20 DEG C.; the welding wire has the advantages of stable electric arc, relatively small spatter and beautiful welding seam forming during use. Chemical components (by mass percent, %) of the welding wire with gas metal arc welding are as follows: 0.06-0.09% of C, 0.40-0.60% of Si, 1.40-1.70% of Mn, 0.4-0.6% of Ni, 0.30-0.50% of Mo, 0.15-0.25% of Cr, 0.02-0.04% of V, 0.05-0.15% of Ti, 0.002-0.005% of B, less than or equal to 0.015% of S, less than or equal to 0.015% of P, less than or equal to 0.0025% of O, less than or equal to 0.0070% of N, and the balance of Fe and inevitable impurities. Ar +20% CO2 argon-rich gas protection is adopted by the welding wire for welding, so that the deposited metal has high low-temperature toughness under the conditions of as-welded and post-welding heat treatment.

Description

technical field [0001] The invention relates to a gas-shielded welding wire, in particular to a 700MPa low-alloy high-strength welding wire for heavy machinery. Background technique [0002] High-strength welding wire is produced with the rapid development of my country's industry in recent years. It is the development goal of 2011-2020 in the "Guidelines for the Development of Science and Technology of China's Iron and Steel Industry". The development of high-strength welding wire is more policy-feasible. As a substitute product for welding rods, welding wire is encouraged by the state to be researched and developed. The project "Technology Development and Application of High-performance, High-quality and Upgraded Products" is a project encouraged by the state. [0003] With the rapid development of heavy machinery such as tower cranes, static pile drivers, construction elevators, submersible drilling machines, high-pressure rotary pile sprayers, and concrete mixers, the a...

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Problems solved by technology

[0004] At present, 700MPa high-strength welding consumables, including welding wires and electrodes at home and abroad, are mostly nickel-molybdenum steel types, such as ER69-3 nickel-molybdenum steel welding wire in the original GB / T8110-1995, with a nickel content of about 0.9% and a molybdenum content of about 0.3 %, other welding materials such as E7018-M and E7518-M are also nickel-molybdenum steel welding materials, the nickel content is about 1.25-2.50%, and the molybdenum content is about 0.3-0.5%. Due to the scarcity of nickel and molybdenum elements, the price is very expensive and cost-effective Poor, ER69-3 welding wire uses carbon dioxide as shielding gas, large spatter during welding and poor forming

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