Technical solution of double-ring laser welding system in stainless steel welding
Posted by： Hangao Time：9/26/2025 9:40:38 AM
I. Project Background
With the widespread use of stainless steel in industries such as food, medical, chemical, and energy, welding quality directly impacts the product's strength, corrosion resistance, and service life. Traditional welding methods suffer from large heat-affected zones, severe deformation, and numerous weld defects. Laser welding, due to its high energy density and controllability, has become an ideal process for stainless steel welding.
This solution, based on a dual-ring laser welding system, achieves a balance between deep penetration welding and thermal management through the synergy of a main beam and an annular auxiliary beam, ensuring weld quality and production efficiency.
II. System Components
Main Light Source (Fiber Laser)
Power Range: 2–6 kW
Purpose: Provides high energy density for deep penetration welding.
Annular Auxiliary Light Source (Semiconductor Laser)
Power Range: 0.4–1.5 kW
Purpose: Provides preheating and slow cooling to reduce stress and cracking risks.
Optical System
Main Spot Diameter: 0.3–0.6 mm
Annular Spot Inner and Outer Diameter: 3–6 mm / 8–12 mm
Energy Distribution: Uniform, avoiding local overheating.
Shielding Gas System
Gas Type: Ar, Ar+N2
Configuration: Surface protection, root protection, and post-weld extended protection.
Control and Monitoring Unit
Weld Pool Image Monitoring
Aspect Ratio Closed-Loop Control
PLC/HMI Real-Time Parameter Adjustment
III. Process Parameter Recommendations
1. Applicable Materials
Austenitic Stainless Steel: 304, 316L, Duplex Stainless Steel: 2205, 2207
2. Welding Thickness Range
0.6–3.0 mm
3. Process Window
IV. Key Process Points
End Face Preparation
Cleaning: Remove oil, scale, and alcohol/acetone wipes.
Assembly: Zero clearance preferred; micro-clearance of ≤0.15 mm is permitted.
Shielding Gas
Austenitic Stainless Steel: Pure Argon Shielding.
Duplex Stainless Steel: Ar + 2–5% N? to Promote Austenite Reforming.
Post-Weld Shielding: 5–10 seconds to Prevent High-Temperature Oxidation.
Thermal Cycle Control
Pre-Weld Ring Beam: Preheats and Stabilizes the Weld Pool.
Post-Weld Ring Beam: Slows Cooling to Reduce Stress and Cracks.
Defect Prevention and Control
Porosity: Improve gas purity and flow rate to extend shielding time.
Cracks: Optimize slow cooling power to reduce stress concentration.
Spatter: Adjust spot energy density to maintain a stable gas flow field.
V. Quality Inspection and Acceptance Criteria
Appearance Inspection: Weld surface is smooth, free of spatter and nodule.
Cross-Section Inspection: Penetration ≥ 90–110% of wall thickness, with no incomplete fusion.
Metallographic Analysis: Duplex stainless steel has a ferrite/austenite ratio of 40–60%.
Airtightness/Pressure Test: Porosity <0.5%, meeting industry standards.
VI. Application Prospects
Straight Seam Welding of Stainless Steel Pipes: Food, Medical, and Chemical Equipment.
Pressure Vessels and Corrosion-Resistant Equipment: Applications requiring high strength and corrosion resistance.
High-End Manufacturing: Aerospace and Energy Equipment.
VII. Conclusion
The dual-ring laser welding system developed by Guangdong Henkel Technology Co., Ltd. achieves a balance between deep penetration welding and thermal management through the synergistic effect of the primary and secondary beams, significantly improving the quality and efficiency of stainless steel welding. This solution is not only applicable to conventional austenitic stainless steel but also meets the high-end welding requirements of duplex stainless steel, providing reliable technical support for the high-end manufacturing industry.
Business Contact
Contact: Manager Xu
Tel: 18942437326
