Submerged arc sintering flux for ferrite-austenite duplex stainless steel and preparation method thereof

Abstract

A submerged arc welding sintering flux (F-A for short) for ferritic-austenitic duplex stainless steel used for welding chemical tankers disclosed by the invention is prepared from solder and potassium sodium water glass, wherein the solder by Al 2 o 3 , CaF 2 、BaF 2 , MgO, SiO 2 、TiO 2 、K 2 O, ferrosilicon, ferromanganese and ferromolybdenum are mixed. The invention also discloses a preparation method of the above-mentioned F-A duplex stainless steel submerged arc sintering flux for chemical transport ships. The composition formula of the present invention has good mechanical properties of the weld metal, high low-temperature impact toughness at -20°C, especially the ratio of ferrite to austenite can be kept at about 1:1, and has excellent corrosion resistance; the welding arc is stable, Smoke and dust, the slag removal in the groove is good, the weld shape is beautiful, and the weld bead transition is smooth and tidy.

Description

Technical field: [0001] The invention relates to the technical field of high-efficiency submerged arc welding for chemical ship inner shell construction, in particular to a flux used in the submerged arc automatic welding process of dual-phase steel and dual-phase steel. In particular, it relates to a submerged arc welding sintering flux for ferrite-austenite duplex stainless steel used in chemical ships and a preparation method thereof. Background technique: [0002] With the development of the chemical industry, especially the rise of the petrochemical industry, the transportation volume of the required raw materials and their products is increasing day by day. A chemical tanker is a liquid cargo ship used to carry various toxic, flammable, volatile or corrosive chemical substances other than petroleum, refined oil and gas. The first generation of bulk chemical tankers were refitted from ordinary tankers in the United States in the late 1940s. No matter in terms of the st...

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Problems solved by technology

[0006] Due to the high alloy content in dual-phase steel, more intermediate phases are likely to be produced in the weld pool, resulting in sticky slag in the weld and difficult slag removal. The duplex stainless steel has a large change in the dual-phase ratio, the mechanical properties of the welded joint are reduced and the corrosion resistance is deteriorated, especially the intergranular corrosion resistance is poor; compared with carbon steel, duplex stainless steel has a larger thermal expansion coefficient and lower heat conduction In the high-efficiency welding process, the input heat is easy to gather around the weld seam, forming a steep thermal gradient, which aggravates the welding deformation. For excessive welding deformation, it is impossible to adopt the commonly used carbon steel due to the fear of the precipitation of harmful phases. thermal orthopedic

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