What are the main production processes used by manufacturers of submerged-arc welding flux?

As an essential component of welding consumables, the production process of submerged-arc welding flux plays a critical role in ensuring welding quality and efficiency. The following are the main process steps typically employed by manufacturers of submerged-arc welding flux during production:

Ingredient Preparation

Ore Screening and Processing : Select appropriate raw materials, such as feldspar, quartz sand, and kaolin. These minerals must undergo rigorous screening and washing to remove impurities and surface contaminants, followed by crushing and grinding to achieve the desired particle size and morphology, thereby meeting the requirements of subsequent processing steps.

Auxiliary ingredient addition : According to the flux formulation requirements, accurately weigh and add various auxiliary ingredients, such as fluorides, aluminum powder, and ferroalloys. These auxiliary ingredients can adjust the flux’s melting point, viscosity, slag-removal properties, and other performance characteristics, thereby improving weld quality and process performance.

Ingredient Mixing

Precise batching : According to the designed formulation, the pre-treated ore and auxiliary raw materials are fed into the batching equipment in the prescribed proportions. The batching process requires strict control of the quantities and ratios of all raw materials to ensure that the flux’s chemical composition and performance meet the specified standards.

Mix evenly : Start the batching equipment to ensure thorough and uniform mixing of all raw materials. During the mixing process, it is essential to control the mixing time and agitation speed to prevent localized non-uniformity or segregation of the materials, thereby ensuring the quality stability of the flux.

Smelting and Sintering

Smelting Treatment : The thoroughly mixed raw materials are charged into the furnace for smelting. The smelting temperature and duration are adjusted according to the specific flux formulation and the characteristics of the raw materials; typically, the process is carried out at high temperatures to ensure complete melting and the occurrence of chemical reactions, thereby forming a homogeneous melt. During smelting, it is essential to carefully control the furnace atmosphere and maintain uniform temperature distribution to prevent overburning or underburning.

Sintering and Forming : The molten material after smelting flows through the discharge port into the forming die for sintering and shaping. During the sintering process, the molten material gradually cools and solidifies, forming a flux block with a specific shape and dimensions. Sintering process parameters, such as sintering temperature, time, and pressure, significantly influence the performance of the flux and must be strictly controlled.

Crushing and Screening

Coarse Crushing : The sintered flux blocks are subjected to preliminary crushing to reduce them to smaller, granular particles. Coarse crushing is typically carried out using equipment such as jaw crushers or hammer mills, with the final particle size determined by the requirements of subsequent processing steps.

Fine Crushing and Screening : The coarsely crushed particles are further subjected to fine crushing and sieving to achieve the required flux particle size distribution. Commonly used screening equipment includes vibrating screens and air-classifying mills. By employing screens with different mesh sizes, the flux particles are graded to produce products within specified particle-size ranges, thereby meeting the requirements of various welding processes.

Quality Inspection and Packaging

Quality Inspection : Conduct comprehensive quality inspections on the produced flux, including chemical composition analysis, particle size distribution measurement, and mechanical property testing. Ensure that all performance indicators of the flux comply with national standards, industry standards, and specific customer requirements; nonconforming products shall be promptly reworked or scrapped.

Packaging and Storage : Qualified flux shall be packaged in accordance with the specified packaging requirements, typically using sealed packaging to prevent moisture absorption, degradation, or other forms of contamination. The packaging must clearly indicate the product model, specifications, date of manufacture, shelf life, and other relevant information, after which the product is stored in the warehouse awaiting shipment.

In summary, the production process of submerged-arc welding flux is a complex and highly precise operation, with each step playing a critical role in determining the performance of the final product. With advances in technology and evolving market demands, the manufacturing processes for submerged-arc welding flux are continually being refined and improved, paving the way for the emergence of more efficient, environmentally friendly, and cost-effective production methods in the future.