Niobium-titanium-boron microalloy high-strength gas protecting welding wire

Abstract

The gas protected Nb-Ti-B micro alloy weld filament contains C 0.04-0.15 wt%, Mn 1.00-2.00 wt%, Si 0.30-1.20 wt%, Ni 0.60-1.80 wt%, Ti 0.08-0.20 wt%, Mo 0.10-0.80 wt%, Nb 0.01-0.05 wt%, B 0.002-0.012 wt%, S not more than 0.10 wt% and P not more than 0.20 wt%, except Fe and inevitable impurity. Under the protection of mixed gas of Ar and CO2 and proper welding technological parameter and interlayer temperature, the weld seam metal can reach tensile strength over 800 MPa and impact power at -30 deg.c higher than 100 J. When used in multilayer welding, the weld seam metal has excellent structure and performance homogeneity, and the weld filament has excellent technological performance. The present invention may be used widely for welding low alloy high strength steel in engineering machinery, railway bridge, marine facility, high pressure container, etc.

Description

Technical field [0001] The invention relates to a niobium-titanium-boron microalloy high-strength gas shielded welding wire. The welding wire uses M21 mixed gas (80%Ar+20%CO 2 ) In protective welding, the welding wire has good process performance, has the advantages of stable welding arc, small spatter, beautiful shape, and adaptability to all-position welding. At the same time, under the conditions of proper control of welding process parameters and interlayer temperature, the yield strength of the weld metal is ≥690MPa, the tensile strength ≥800MPa, and the impact energy of -30℃ is A kv ≥100J, suitable for gas shielded arc welding of 800MPa grade low alloy high strength structural steel. Background technique [0002] At present, in the design and manufacture of important large-scale welded structures for marine vessels, engineering machinery, and oil pipelines, in order to reduce dead weight, reduce energy consumption, and increase service life, structural steel plates with bot...

AI Technical Summary

Problems solved by technology

However, the variety of gas shielded welding wire is single, so far, there is no mature 800MPa commercial gas shielded welding wire

Japanese patent P2000-218391A discloses a gas shielded welding wire, the weld metal of the welding wire has good low temperature impact toughness, but the disadvantage is that the tensile strength cannot reach 800MPa

In the gas-shielded welding wire disclosed by Japanese Patent JP3-52795A, alloying elements such as trace Nb, Ti and B have been compounded. Addition mismatch, easy to increase the hot cracking tendency of weld metal; Ti content (0.01-0.10wt%) is low, not conducive to stable transition to the weld to promote the formation of fine acicular ferrite

Although the tensile strength of the deposited metal has reached 800MPa for ST800 mixed gas shielded welding wire produced by ESAB, its shortcoming is that its impact toughness cannot meet the requirements of the structure in low temperature service.

The strength and toughness of the corresponding weld metal of this welding wire can match the 800MPa grade steel plate, but because a large amount of noble metal nickel (≥3.85wt%) is added to the welding wire, the cost is high