Determination of the Effect of Heat Input during Laser Welding on the Magnitude of Residual Stresses in the Refurbishment of Al Alloy Casting

The paper presents the results of research on the evaluation of the quality of coating layers made by a laser. The base material, which was Dievar steel (1.2343), was coated with a single layer using additional materials in the form of a wire with a diameter of ø 1.0 mm. As additional material, wires with chemistry corresponding to steels 1.2343 and 1.6356 were used. The primary objective was to verify the possibilities of innovative use of additive materials based on maraging steels, which were chosen from the production of two manufacturers with slightly different chemical compositions. The experiment verified the influence of the cladding parameters on the residual stress values around the fabricated maraging layers. Metallographic analysis by light microscopy was carried out in order to identify the individual structures as well as to assess the occurrence of internal defects in the coatings. The effect of the mixing of the coating metal with the base material was also assessed by means of a low-load hardness assessment, which was carried out in accordance with EN ISO 4063-2. Based on the results, it can be concluded that, in terms of residual stresses, the measured values were approximately the same for all the additive materials used; however, due to the desired mechanical properties of the additively formed layers, it is possible to recommend additive materials based on medium- and high-alloy steels for additive manufacturing.