Welding and Weld Seam Treatment Process for African Rural Lighting Ready Board Box Body

In rural Africa, the humidity is high and the temperature difference between day and night is large, accompanied by salt spray, condensation, and wind erosion. Therefore, carbon dioxide gas shielded full welding is preferred for the welding of lighting ready board bodies. The corner joints must be continuously welded, and spot welding is only used for assembly positioning and cannot be used as the final forming weld seam. Argon arc welding is mostly used for stainless steel box bodies, and ordinary carbon steel box bodies are not recommended, which is costly and inefficient in production. There are gaps in the spot welding seam, and water vapor and salt spray are easily infiltrated. The inner side of the weld will preferentially rust, causing the box to leak and fail; Full welding achieves complete sealing of the joint, blocks water vapor infiltration, and balances structural strength and outdoor waterproofing ability. The welding adopts segmented skip welding technology to control sheet metal thermal deformation, avoid stress cracking at the bending of the box, and eliminate porosity, undercutting, and weld through defects in the weld seam.

The welding treatment of the lighting ready board body is divided into two processes: post welding mechanical treatment and pre-treatment. After welding, first use an angle grinder to remove welding slag and splashes, polish and smooth the weld seam, eliminate sharp burrs, and ensure that the weld seam is not excessively polished to thin the base material. Complete the box shaping and correction, and check for micro crack defects in the weld seam. Afterwards, it enters the complete pre-processing process: alkaline degreasing and oil removal, multi-stage water washing, zinc based phosphating treatment, generating a dense phosphating film on the surface of the weld and box to improve the adhesion of the spray coating. The phosphating quality at the weld position is particularly critical to prevent the plastic layer from cracking and falling off.

After completing the pre-treatment, electrostatic spraying should be carried out to ensure that the paint film thickness of the weld seam meets the standard. The primer and topcoat should cover the weld seam completely to prevent the weld seam from being exposed. The weld seam is a high-risk area for corrosion of the box body. Only when the welding seal is in place, combined with a complete set of processes such as grinding, phosphating, and complete spraying, can it meet the long-term outdoor salt spray and condensation conditions in rural Africa and extend the service life of the box body.