The core of laser cleaning of welds lies in selecting the right laser type and matching it to the weld, rather than simply pursuing high power. As a leading company in laser cleaning, SDQY Laser specifically points out that weld cleaning scenarios should focus on three core indicators:

1. Pulse Width Matching: Use 10-20ns short-pulse lasers to remove thick oxide scale, utilizing peak power to overcome adhesion; switch to 50-100ns medium-pulse lasers for precision welds (such as stainless steel medical devices) to avoid expanding the heat-affected zone.

2. Wavelength and Material Matching: For carbon steel and low-alloy steel welds, prioritize 1064nm infrared lasers with an absorption rate exceeding 85%; for non-ferrous metals such as aluminum alloys and titanium alloys, use 532nm green lasers to address the high infrared reflectivity issue, improving cleaning efficiency by 30%.

3. Power Density Control: The key lies in "gradient control"-the power density at the weld edge is reduced to 3-5kW/cm² to prevent substrate melting; the power density in the central contaminant concentration area is increased to 8-12kW/cm² to ensure thorough cleaning.

Three Key Details Determine Cleaning Effectiveness and Substrate Safety

1. Spot Control: From Fixed to Dynamic Adaptation
Traditional fixed spot cleaning often leads to incomplete cleaning or scratches at the weld root. Advanced techniques include: Utilizing an adjustable focus spot system, adjusting the spot diameter (0.5-2mm) in real-time according to the weld width (2-10mm) to ensure complete coverage; Using a "spiral scanning mode" for fillet welds and butt welds with a scanning galvanometer to avoid spot overlap and localized overheating.

2. Cleaning Path Planning: Avoiding the Pitfalls of Unidirectional Scanning
Efficient cleaning hinges on path optimization: Prioritizing bidirectional cross-scanning with a path overlap rate of 30%-50%, preventing missed areas and reducing substrate damage; Employing "layered cleaning" for multi-layer welds: surface spatter (5-7kW/cm²) → interlayer oxide scale (8-10kW/cm²) → surface polishing (3-4kW/cm²).

3. Environmental and Auxiliary Technologies: Ensuring Stealth and Stability
Details easily overlooked in industrial settings directly impact consistency:

• Inert Gas Protection: When cleaning stainless steel and titanium alloys, use argon gas at a flow rate of 5-8 L/min to prevent secondary oxidation.
• Dust Removal and Temperature Control: Use a negative pressure dust removal system (negative pressure ≥ -0.06 MPa) to prevent dust from interfering with laser transmission; during continuous operation, ensure the substrate temperature is ≤200℃, and activate intermittent mode if the temperature exceeds the threshold.

Common Problems and Practical Solutions:

• Residual Oxide Scale: Adjust the spot diameter and scanning range to ensure coverage of weld edges; specifically increase the power density by 5%-10% to reach the oxide layer peeling threshold.
• Substrate Micro-melting Marks: Often caused by pulses that are too short or scanning too slow. Extend the pulse width by 20%-30% and increase the scanning speed to 100-150 mm/s.
• Lower-than-Expected Efficiency: Check the wavelength and material matching (infrared laser efficiency drops by 50% for aluminum alloys); change unidirectional scanning to bidirectional cross-scanning.

Industry Application Trends: Intelligentization + Customization
SDQY Laser's weld cleaning technology is upgrading towards "intelligentization + customization": equipped with a vision recognition system, it automatically identifies the position and width of the weld, and realizes real-time adaptation of the spot and power; for high-end fields such as nuclear power and aerospace, it develops customized equipment with adjustable pulse energy to meet the high-precision cleaning needs of welds of different materials.