The DQ-Series was used by ThyssenKrupp Tailored Blanks in Germany for removing metallic coatings from their manganese boron steel tailored blanks.
Compared with conventional steel, the tensile strength of these steels, especially after a heat treatment, is much bigger. This allows for reduced sheet metal thicknesses without reducing the strength of the structures.
However, the steel alloys were coated with aluminium silicon, which prevented them from being used with laser welded tailored blanks. This is because the coating would mix with the basic material in the weld seam during welding.
To prevent such problems the client chose to remove the coating in the area of the weld seam. After consultation with Rofin, it found any kind of metallic coating can be removed from tailored blanks using q-switched lasers.
The new method was faster and less expensive than the process of sandblasting the coat off, so the company went with a 450W laser.
Three classes of lasers are available. Standard comes with powers from 350 to 850W, and work with round fibre diameters of 600 micrometre. Premium comes with 500W, and works with 600 micrometre round or square fibre diameter, while Premium+ is 800W, with 800 micrometre fibre diameter compatibility.
The premium versions also come with an optical attenuator which supports a very fine and long-term stable parameter adjustment for sensitive applications such as the selective removal of coating layers.