Welding wire used for FCB method high heat input submerged arc welding and preparation thereof, welding flux and preparation of welding flux, welding material and application of welding material

Abstract

The invention belongs to the technical field of submerged-arc welding, and provides a welding wire used for FCB method high heat input submerged-arc welding and preparation thereof, a welding flux and preparation of the welding flux, and a welding material and application of the welding material . On the basis that the corrosion-resistant elements of Cu, Ni, Cr and Mo are added into the welding wire, the content of P in the welding wire is controlled to be smaller than 0.005%, and the content of S in the welding wire is controlled to be smaller than 0.002%, so that the welding wire has excellent seawater / hydrogen sulfide corrosion resistance; meanwhile, the welding wire has good wire feeding stability at the large welding speed, is suitable for 50-200 kJ / cm high heat input FCB method submerged-arc welding, and the production efficiency is greatly improved; and a nucleating agent containing lanthanum, cerium, yttrium and titanium is added into the welding flux, grain coarsening under the high heat input welding condition is inhibited, a welding seam forms acicular ferrite interlocking structures which are interwoven and occluded with each other, the grain is refined, the strength and toughness and crack resistance of weld metal are improved, meanwhile, the shape and size of inclusions are effectively controlled, and therefore, the corrosion resistance of the welding seam is considered.

Description

technical field [0001] The invention relates to the technical field of submerged arc welding, in particular to a welding wire used in FCB large input energy submerged arc welding and its preparation, flux and its preparation, welding material and its application. Background technique [0002] With the rapid development of the national economy, my country's demand for oil imports continues to increase. Oil imports mainly rely on oil tankers for transportation. The inner walls of cargo oil tanks of oil tankers serve under the multiple corrosion conditions of seawater and hydrogen sulfide-rich humid atmosphere. The corrosion resistance requirements of welded joints are relatively high. In order to improve the service life of oil tankers and reduce the maintenance difficulty and coating cost of cargo oil tanks, marine corrosion-resistant steel and supporting welding materials have been widely used in the construction of oil tankers in recent years. With the rapid growth of oil t...

AI Technical Summary

Problems solved by technology

At present, in order to ensure the mechanical properties and corrosion resistance of welded joints at the same time in the welding production process of oil tankers, domestic shipping companies usually only use welding methods with small heat input (<40KJ / cm), resulting in reduced production efficiency and increased production costs , unable to meet the needs of modern economic development

[0003] Chinese patent CN200910272211.X discloses a seawater corrosion-resistant submerged arc welding wire, which has the characteristics of corrosion resistance, high strength, good toughness, and strong resistance to welding cold cracking. Its tensile strength is greater than 600MPa, and its low-temperature impact performance Akv ≥65J, but the submerged arc welding wire he invented did not involve the application of hydrogen sulfide corrosion conditions

At the same time, the welding heat input range in this patent is only 10-22kJ / cm

[0004] Chinese patent CN201510271104.0 discloses a special submerged arc welding wire for corrosion-resistant steel welding. Its tensile strength is greater than 500MPa, and the low-temperature impact value KV2 (-40°C) of the deposited metal is greater than 90J. It matches well with corrosion-resistant steel plates and is most suitable for use with corrosion-resistant steel plates. The flux SJ105G is used together to meet the corrosion resistance requirements of corrosion-resistant steel plates, but the submerged arc welding wire invented by it does not involve the welding process and application under the condition of large input energy

[0006] The heat input of FCB large-line energy submerged arc welding is relatively high, generally greater than 50kJ / cm, which will lead to severe coarsening of the weld metal grains, which will have an extremely adverse effect on the strength and plasticity of the welded joint.

Through oxide metallurgy, that is, by adding oxide particles and using oxide inclusions as nucleation cores, the grain growth of the weld under large input energy is inhibited, and the strength and toughness of the weld are improved, but the oxidation in this method Inclusions will lead to a decrease in the corrosion resistance of the weld

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