Container House Full-Weld Standard

The full-weld standard for container houses mainly involves welding requirements for roof joint seams, structural frames, and special-scenario applications, which must meet core indicators such as no cold welds, full welds, and anti-corrosion treatment.

1. Full-Weld Standard for Roof Joint Seams

The full-weld roofing process is crucial for eliminating leakage risks, with the following core requirements:

1. Full Seam Coverage: All spliced seams on the roof must undergo continuous full welding to ensure no residual gaps. For example, after adopting the full-weld roofing process in the production of folding containers, no leakage occurred in the houses during heavy rainfall, validating its waterproofing effectiveness.
2. Weld Quality: Welds must be uniform and smooth, free from cracks, undercuts (depth ≤ 0.5mm), incomplete fusion, and other defects. The welding standard for energy storage prefabricated cabins explicitly requires that weld appearance inspections comply with non-destructive testing specifications (e.g., 20% ultrasonic testing sampling).
3. Composite Layer Matching: After full welding, a waterproof and thermal insulation composite layer must be applied to achieve multiple effects such as waterproofing, fire resistance, and thermal insulation. For example, after adopting a waterproof and thermal insulation composite layer on the roof of foldable integrated houses, the indoor temperature in summer was 4°C lower than that of ordinary quick-assembly containers.

2. Full-Weld Standard for Structural Frames

The welding quality of steel structural frames directly affects the load-bearing capacity and durability of the house:

1. Main Beam and Column Welding: The steel thickness of main beams and columns must meet standards (e.g., the steel thickness of national standard container frames must satisfy mechanical calculation requirements), and the welding process must be full without cold welds. The Hubei Container Customization Guide emphasizes that the details of the welding process determine the safety of the container house during lifting, stacking, and transportation.
2. Anti-Corrosion Treatment: The weld area must undergo overall galvanization or be sprayed with an anti-corrosion coating (e.g., epoxy zinc-rich primer) to extend its service life. After welding, the carbon steel cabin body of energy storage prefabricated cabins must be sandblasted to Sa2.5 grade and coated with an epoxy zinc-rich primer (80μm) + polyurethane topcoat (60μm).
3. Critical Weld Grade: According to the Modular Building Technical Standard, critical welds must meet corresponding grades. For example, the main frame welds of energy storage prefabricated cabins must meet the welding requirements for high-strength steel (e.g., Q355B steel using ER50-6 welding wire).

3. Full-Weld Requirements for Special Scenarios

For different usage scenarios, the full-weld standard needs further refinement:

1. High-Humidity or Coastal Areas: Weathering steel or stainless steel must be used, and the heat input during welding of dissimilar steels must be controlled to avoid carbon migration. For example, energy storage prefabricated cabins in coastal areas must use galvanized sheets, stainless steel, or be sprayed with an anti-corrosion coating.
2. Fire and Explosion-Proof Scenarios: Welds must meet fire resistance limits (e.g., 1-hour fire resistance requirement), and fire barriers must be installed between battery compartments and electrical compartments. Intermittent welding should be used to avoid high-temperature damage to fireproof materials.
3. Sealing Requirements: The cabin roof and side panels must undergo continuous full welding, and sealant (e.g., polyurethane sealant) must be applied after welding. Airtightness testing must be conducted (pressurized to 500Pa and held for 30 minutes, with a pressure drop ≤ 10% considered qualified).