Due to favourable mechanical properties and lower production costs in high-volume production, cast products are very widespread across different industries and constructions. Different product phases require welding and reparation using repair welding. Laser welding of grey cast iron is very challenging due to its poor weldability. In fact, the chemical composition of grey cast iron causes large problems related to weldability, reflected in the incidence of cracks and alloy foam. Successful laser welding can be ensured by selecting the appropriate workpiece preheating temperature, technological parameters and appropriate filler material. In the paper, we studied and presented basic characteristic properties of materials and the effect of filler materials on welding of different types of grey cast iron. Welding of the studied alloys was presented, with an emphasis on laser welding. We conducted laser welding of ductile and lamellar grey cast iron using different filler materials. Welding joints were assessed carrying out a visual inspection, a metallographic analysis and hardness measurements. Based on the measurements conducted, we assessed the graphs showing joint hardness depending on the joint depth. Stemming from a visual analysis, microscopy and hardness measurements, we would select the NiTi4 filler material for the welding of the nodular cast iron. Except for then small local porosity on the sample, the weld contained no major irregularities. Average weld hardness was 389.7 ± 86.3 HV0,3. For the welding of lamellar cast iron, we would choose between the AMPCO and NiTi4 filler materials, as both yielded good results. Average weld harness of AMPCO was 391.5 ± 165.7 HV0,3, while the average weld hardness of NiTi4 was 356.5 ± 59.5 HV0,3.
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