Flux-cored wire

Abstract

The invention discloses a flux-cored wire, which relates to a flux-cored wire with medicinal powder filled in a soft steel sheath that is specially used for gas shielded arc welding. Each component of the medicinal powder has the following percentages by weight relative to wires: 3.0% to 11.0% of TiO2; 0.02% to 0.10% of C; 0.3% to 1.2% of Si; 0.7% to 2.0% of Mn; 0.1% to 1.5% of Ni; 0.1% to 1.2% of Mo; 0.0010% to 0.0045% of B; 0.05% to 1.00% of the sum of any one or more than two elements of Na, K, Li and Cs; 0.05% to 1.00% of the sum of any one or more than two elements of Mg, Ca, Ba, Al and Zr; balance iron powder and irremovable impurities, and the composition of each element satisfies the conditional expression that C+Si / 25+Mn / 5+Ni / 40+Mo / 5 is greater than or equal to 0.25 and is less than or equal to 0.60; the electric arc welding for gas shielding at the conditions that the maximum welding heat is 60KJ / cm and the maximum interlayer-temperature is 350 DEG C has excellent welding operation, fine welding metal intensity of tension and impact ductility.

Description

technical field [0001] The invention relates to a flux-cored welding wire for gas-shielded arc welding. Background technique [0002] Recently, some changes have taken place in the steel used in steel structures, bridges and construction fields. In the past, mild steel and steel with a tensile strength of 490Mpa were mainly used, but recently, the demand for steel with a tensile strength of 520Mpa has increased sharply for the purpose of enhancing shock resistance and lightweight steel, thereby saving costs; [0003] However, the development of flux-cored wires that meet these requirements and the special welding environment on site, and meet the high heat input and interlayer temperature conditions is almost blank; [0004] As a steel welding material with a tensile strength of 520Mpa, Korean Patent No. 2006-0050038 records the control of the sum of C, S, Mn, S, Ti, Mo, Cu, Mn and Mo contents; the sum of Si and Ti contents; And solid wire for gas-shielded arc welding with...

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Problems solved by technology

[0005] But strictly speaking, the gas shielded arc welding solid core wire proposed in the public license can only be applied to the priority range of the maximum welding heat of 40KJ / cm, and can only weld steel with a tensile strength below 520Mpa, and compared with the flux core Welding wire, the workability of solid welding wire is low, so the use ratio in the market is decreasing day by day;

[0006] Flux-cored welding wires can be welded at high heat input and interlayer temperatures that meet on-site welding conditions, and have excellent workability and mechanical properties. The need for its development is increasing, but no one has yet proposed a concrete proposal.

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