Laser cladding is a precision process for applying protective metal coatings on workpieces. Using a one dimensional scanner, the laser spot can be oscillated quickly, changing the effective size of the laser spot. This can significantly change the shape and quality of layers in laser wire cladding. In this investigation, the influence of this scanner based spot size change on the geometry of welded seams and on layers produced by multiple welded seams is described. On the upper geometry of the seams, the height and the width will be considered and on the lower geometry, the penetration, welding defects and pores. Defects on the substrate surface on the side of the seam are discussed, since this may lead to welding defects in subsequent seams. Also, the wire feed speed has been varied, which led to different sized seams and a change in deposited material per time. This has a significant effect on the dilution as will be shown in this paper. The tests have been performed using a diode laser continuously emitting about 640 W of radiation. The substrate material was S235 mild steel and the deposition material martensitic chrome silica steel (1.4718) supplied as a 0.8 mm diameter wire.
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