Submerged Arc Welding Flux Manufacturer: Applications in the Steel Structure Industry

Submerged Arc Welding Flux Manufacturer: Applications in the Steel Structure Industry

Submerged Arc Welding Flux Manufacturer: Do you understand the functions of submerged arc welding flux? Are you familiar with its chemical composition? Do you know what role it plays in various industries? If you’re unsure about these questions, pay attention to the role of submerged arc welding flux in the steel structure industry.

Submerged Arc Welding Flux Manufacturer: I. Reference Chemical Composition of the Flux

Silicon dioxide, titanium dioxide, calcium oxide, magnesium oxide, aluminum oxide, manganese oxide, calcium oxide, sulfur, phosphorus

35-45 20-30 20-30 5-15 0.06 0.08

Submerged Arc Welding Flux Manufacturer: II. Mechanical Properties: Mechanical Properties of the Deposited Metal:

Using welding wire, tensile strength (MPa), yield strength (MPa), elongation

Submerged Arc Welding Flux Manufacturer: III. Explanation:

The flux is a silica–calcium neutral sintered flux with an alkalinity of approximately 1.0. It appears as gray, spherical particles, has a bulk density of 1.23 g/cm³, and a particle size range of 10–60 mesh. It can be used with both AC and DC power sources; when welding with DC, the electrode is connected to the anode. During welding, the arc burns stably, slag removal is easy, and the weld bead exhibits excellent appearance. The silicon content in the weld increases markedly, while manganese transfers from the flux into the weld metal. The slag is of the “short-slag” type, and no dripping slag occurs when welding small-diameter circumferential seams, making this flux particularly suitable for such applications. It is also well suited for high-speed welding.

Submerged Arc Welding Flux Manufacturer: IV. Usage:

With appropriate welding wires (such as H08A, H08MnA, and H08MnA) and fluxes, this process is suitable for welding Q235 ordinary carbon steel, boiler steel, and pipeline steels of grades A, B, X42, and X46. It is also applicable to the welding of steels used in pressure vessels, such as liquefied petroleum gas tanks and gas cylinders.

Notes on verbs (abbreviation for “verb”):

Preheat to 350°C for 2 hours before welding. Rust, oil, water, and other contaminants must be thoroughly removed from the weld area.

Submerged Arc Welding Flux Manufacturer: Classification of Submerged Arc Welding Flux

The primary functions of flux in submerged arc welding are to form a slag that isolates the weld from the atmosphere and to control the chemical composition of the weld metal, thereby ensuring satisfactory mechanical properties and preventing defects such as porosity, cracks, and slag inclusions. Depending on the requirements of the welding process, the flux must also exhibit good arc-stabilizing characteristics and produce a slag with appropriate density, viscosity, melting point, particle size, and permeability, so as to ensure proper weld bead formation. Finally, the slag shell formed upon solidification should possess excellent slag-removal properties.

Currently, China primarily classifies welding fluxes based on their manufacturing method and chemical composition. According to the manufacturing method, welding fluxes can be divided into fused fluxes, sintered fluxes, and bonded fluxes.

Melting flux is produced by mixing raw materials according to a specified formulation in a melting furnace, followed by granulation and water-cooling drying. The resulting product is then screened and packaged. Sintered flux and bonded flux, on the other hand, are non-smelting fluxes that are manufactured by wet-mixing raw powder according to a formulation, drying, pulverizing, and sieving. The key difference is that sintered flux is dried (or sintered) at 400–1000°C, whereas bonded flux is dried at 350–400°C. Melting flux features uniform composition, high particle strength, low moisture absorption, and good storage stability, making it the most widely used type of flux in China today. Its drawback is that deoxidizers and ferroalloys cannot be added to the flux, as they suffer substantial burn-off during the melting process.

Sintered flux is characterized by the ability to add deoxidizers and ferroalloys to the flux during each high-temperature melting cycle, thereby transferring substantial amounts of alloying elements into the weld metal and compensating for the burn-off of alloying elements from the welding wire. It is commonly used for welding high-alloy steels or for surfacing applications. In addition, sintered flux exhibits excellent slag-removal properties, making it particularly suitable for narrow-gap submerged-arc welding of thick-section workpieces.