Abstract
The welding quality of stainless steel sinks directly affects their corrosion resistance, sealing and service life. This article deeply analyzes the technical points of six mainstream welding processes such as TIG welding, MIG welding, and laser welding. Combining the American Welding Society (AWS) standards and German industrial cases, it reveals the industry secret of increasing weld strength by 30%, and attaches a comparison table of authoritative agency test data and process parameters.
1. TIG welding: the preferred solution for precision thin-wall processing
The American Welding Society (AWS D18.1 standard) clearly states that TIG welding is irreplaceable in 0.8-3mm thin plate processing. When using argon gas protection with a purity of 99.99%, the weld oxidation rate can be reduced to less than 0.3% (data source: International Welding Institute IIW). Technology innovation:
- Pulse current technology (frequency 2-5Hz) is used to reduce heat input by 40%
- Back argon protection system eliminates root oxidation defects (reference case: German Blanco high-end sink production line) Quality control points: The tungsten tip angle must be maintained at 15-30°, and 100% penetration testing (PT) must be performed after welding
2. MIG welding: an efficient solution for thick plate processing
According to the EU EN ISO 14341 standard, when 1.2mm welding wire is used with 92%Ar+8%CO₂ mixed gas, the penetration depth can reach 1.5 times that of the traditional process. Japanese JIS Z3312 standard recommends:
- X-shaped groove design is used when the plate thickness is ≥3mm
- The welding speed is controlled in the range of 35-50cm/min Industry application case: Franke bathroom uses a digital MIG welder to achieve continuous production of 15 meters of welds per hour (for equipment parameters, see Swiss Welding Equipment Association SWISSMEM)
3. Laser welding: the future trend of micron-level precision
The latest research by TRUMPF in Germany shows:
- Fiber laser (wavelength 1070nm) can reduce the heat-affected zone to 0.2mm
- The strength of the lap joint is increased to 95% of the parent material (only 85% for traditional processes) Technology breakthrough:
- Real-time visual monitoring system achieves ±0.05mm positioning accuracy
- Synchronous wire feeding technology solves the problem of thin plate burn-through (for technical details, see American Laser Society LIA)
4. Resistance spot welding: invisible reinforcement technology for frame structures
Tests by POSCO Stainless Steel Research Institute in South Korea show:
- A 5mm diameter weld nugget can withstand 800N shear force
- The electrode pressure needs to be precisely controlled within the range of 2.5-3.5kN Technical points:
- CrZrCu electrodes are used to ensure a service life of 20,000 times
- The welding cycle must include 3 stages of pressurization procedures (pre-pressing-welding-maintaining pressure)
5. Plasma arc welding: an innovative solution for connecting dissimilar materials
For mixed welding of 304 and 430 stainless steel:
- Argon-hydrogen mixed gas (H₂ content ≤5%) is required
- When the arc compression reaches 95%, a high-quality weld with a depth-to-width ratio of 3:1 can be achieved Certification standards: Comply with ASME BPVC Section IX P-No.8 Material Group Requirements
6. Ultrasonic welding: an innovative process that is environmentally friendly and traceless
The 2023 report of the British Welding Institute (TWI) pointed out:
- 20kHz high-frequency vibration can reduce the interface temperature by 300℃
- Especially suitable for 0.3-1.2mm decorative seams Environmental advantages:
- Zero gas consumption
- Energy consumption is only 1/3 of traditional processes
7. Quality control system (additional emphasis)
- Material certification in accordance with ASTM A480 standard
- Salt spray test must reach 500 hours without red rust (refer to ISO 9227 standard)
- Digital welding management system (WMS) real-time monitoring of 17 process parameters
Summary
From the precise control of TIG welding to the environmental innovation of ultrasonic welding, modern welding technology has formed a complete quality pyramid system. It is recommended that manufacturers refer to the latest technical white paper of the International Stainless Steel Forum ISSF (https://www.worldstainless.org) and establish a full-process quality control system in combination with the German VDI 3822 standard. When selecting a welding process, it is necessary to comprehensively consider product positioning (high-end/popular), production capacity requirements (single piece/batch) and environmental protection requirements in order to establish a technical moat in the fierce market competition.