A seamless flux-cored welding wire for high-strength steel welding in marine engineering

Abstract

The invention discloses a seamless flux-cored welding wire for high-strength steel welding in marine engineering. The seamless flux-cored welding wire includes a low-carbon steel strip sheath and core powder, and the mass of the low-carbon steel strip sheath accounts for the total mass of the seamless flux-cored welding wire 80% to 90% of the core powder, the mass of the core powder accounts for 10% to 20% of the total mass of the seamless flux cored wire; wherein the core powder includes the following components in mass percentage: 43% to 48% of rutile, Quartz 1%~2%, sodium fluoride 1.2%~2%, potassium titanate 3.5%~5.5%, bismuth oxide 0.05%~0.1%, high carbon ferromanganese 8%~11%, nickel powder 5.5%~8.5% , rare earth ferrosilicon 3%~4.8%, magnesium powder 1.5%~3.5%, and the balance is iron powder. The seamless flux-cored wire is a seamless flux-cored wire for marine engineering high-strength steel. The weld formed by welding with the seamless flux-cored wire has excellent performance after heat treatment, has a good yield ratio, and has high impact at low temperature Toughness, the impact energy of the deposited metal is not less than 90J at ‑60°C, and can be applied to the welding of high-strength steel plates for marine engineering.

Description

technical field [0001] The invention relates to the field of welding materials, in particular to a seamless flux-cored welding wire for high-strength steel welding in ocean engineering. Background technique [0002] With the continuous development of offshore oil and gas, my country has invested in the construction of many oil and gas platforms. Due to the harsh working environment of marine engineering equipment, the requirements for steel and supporting materials for marine engineering equipment are relatively high. Therefore, the demand for upgrading marine engineering equipment has been very high. strong. In terms of welding materials, high-strength steel supporting welding materials mainly rely on imports, and the lack of independent high-strength steel welding materials restricts the development of my country's marine engineering equipment industry. Therefore, it is urgent to carry out research and development of high-strength steel welding materials for marine engineer...

AI Technical Summary

Problems solved by technology

After the heat treatment of the existing flux-cored wire weld metal, the structure is coarsened, and a large number of carbides and impurity elements are precipitated at the grain boundaries, resulting in a significant drop in its low-temperature impact energy, which cannot meet the -60°C KV 2 The construction requirement of ≥80J, for example, the Chinese patent with the publication number CN104526188A discloses a seamless flux-cored welding wire that can be treated for stress relief after welding. The welding wire has low alloy content (Ni content less than 0.5%) and poor impact toughness. Cannot meet -60℃KV 2 The requirement of ≥80J; the Chinese patent with the publication number CN106624449A discloses a flux-cored welding wire for heat treatment of large and thick plates in marine engineering and its preparation method and application. 4.6% of the total weight of the welding wire, less slagging agent is not conducive to achieving good welding processability, and the impact toughness of the welding wire weld metal is poor (-40 °C KV 2 The minimum is 47J), which cannot meet the -60°C KV 2 The requirement of ≥80J; the Chinese patent with publication number CN109623193A discloses a seamless flux-cored welding wire for low-temperature steel with low hydrogen and high toughness and its preparation method. The flux-cored welding wire of this invention is used for welding low-temperature storage tanks, and the weld seam is As welded, it cannot meet the requirements for weld microstructure and mechanical properties after heat treatment, and the types of raw materials used in core powder are quite different

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