The research involved the analysis of test results concerning the effect of laser surfacing process conditions on the characteristics of an overlay weld made of alloy Stellite 694 on the substrate of nickel superalloy Inconel 738LC as well as the determination and specification of the most common overlay weld imperfections. The overlay weld subjected to the tests was made using a Yb:YAG disc laser having a power of 1 kW and a filler metal in the form of powdered Stellite 694 cobalt alloy. The research led to the development of process conditions and the identification of major overlay weld imperfections including lacks of penetration, gas pores and microcracks in the base material. The formation of above-named imperfections could be ascribed to low laser radiation power density (< 30 kW/cm²), the excessive overlap of consecutive tracks (> 60% of the single track width) and the insufficient gas shielding of liquid metal in the weld pool.

doi: 10.17729/ebis.2017.4/3