The article presents tests aimed to develop technological parameters of the plasma surfacing of Inconel 625 overlay welds onto boiler tubes (φ 45 × 5 mm) made of steel 13CrMo4-5, providing the content of iron on the overlay weld surface below 5%. The research work involved macroscopic metallographic tests of overlay welds, the identification of the chemical composition of the overlay weld surface as well as microscopic metallographic tests and the microanalysis of the chemical composition across the overlay weld. It was ascertained that, under certain conditions, the use of plasma surfacing enables the obtainment of high-quality single-run overlay welds having a thickness of below 2 mm and characterised by the minimum stirring of the overlay weld metal with the substrate metal as well as the obtainment of an iron content of 2.5% on the overly weld surface.

doi: 10.17729/ebis.2018.1/1