Compared to traditional welding methods, laser welding has significant advantages - low heat input, fast welding speed, small heat-affected zone, small thermal deformation, etc. In recent years, laser welding has been widely used in the automotive industry, shipbuilding industry, nuclear power industry, aerospace industry and other high-tech industries are increasingly widely used, and with the The cost of complete sets of equipment to reduce the application of everyday hardware and other life-related areas began to grow rapidly.
In order to meet the needs of the development of various industries, laser welding methods have also been improved and progressed. Laser filler welding has become an effective alternative to traditional arc welding in the rail transportation and automotive industries because of its concentrated welding energy and small deformation, which can reduce the gap margin during butt welding and reduce welding defects.
Today, we will introduce you to the advantages of laser filler welding.
When laser fillet welding, the laser is usually a high power fiber laser
The laser not only needs the wire, but also needs to melt the base material and the formation of laser deep fusion welding unique small hole effect on the base material, forming a deeper molten pool, the composition of the wire and the base metal components fully mixed to form a new mixed molten pool, the mixed molten pool of elemental composition and its proportion, quality relative to the wire and the base material has a large difference, so you can choose the right wire for the performance defects of the base material itself added to the welding process, thus improving the crack resistance, fatigue resistance, corrosion resistance, and wear resistance of the weld on a microscopic level with purpose.
In addition, laser filler welding allows for multi-pass stack welding, as it enables deep fusion welding with a small hole effect, which allows for full fusion of the upper and lower layers and avoids serious defects that are not fused, thus providing the ability to weld large thickness joints.
With the development of laser filler welding technology and the increase of the upper power limit of the laser, the application of laser filler welding is becoming more and more widespread:
Application areas of laser filler welding
- Laser filler welding of aluminum alloys
- Laser filler welding of dissimilar metals
- Improvement of weld seam formation
- Narrow gap filler welding
For two of the applications, namely, improvement of weld seam formation and narrow gap filler welding, let's see the effect of laser filler welding with practical application examples.
Improvement of weld seam forming
Requirement: 1mm and 3mm stainless steel sputtering welding, requiring weld seam without porosity and better forming.
Equipment: 4000W continuous fiber laser (fiber core diameter 200μm), wire feeder, welding head.
Result: Good forming, no porosity in the weld seam, the forming and cross-sectional shape of the weld seam as shown in the picture below.
a. 1mm+1mm
b. 1mm+3mm
c. 3mm+3mm
Narrow gap laser fillet multi-pass welding
Requirements: 18mm thick Q345 marine steel plate sputtering welding, requiring less porosity in the weld, no unfusion, higher tensile strength of the joint than the parent material, and better weld formation.
Equipment: Rike 6000W continuous fiber laser (fiber core diameter 400μm), wire feeder, welding head.
Result: The forming is good, no unfused, the weld is basically free of porosity, as shown in the following picture, and the tensile test proves that the weld fractures in the base material, indicating that the tensile strength of the joint is higher than that of the base material.
For the commonly used material butt joint laser fillet welding, in order to improve the weld formation, it is generally recommended that the laser and fiber core diameter, welding head configuration should ensure that the focused spot diameter is between 0.4mm and 0.6mm, and the wire should be selected as the appropriate grade.
