Influence of WAAM process parameters on the composition and structure of the Sv-08G2S – Sv-07Kh25N13 layered bimetallic composite

Currently, more and more attention is being paid to additive technologies from the side of real production. This is due to the unique capabilities to create complex, large-sized blanks with functional gradient properties. Particular attention is paid to the creation of products made of layered composite bimetallic materials. The most popular materials systems include bimetals of the “low–alloy carbon steel - stainless chromium-nickel steel” type, which are widely used in the energy, military and aerospace industries. One of the ways to produce such products is the technology of electric arc cultivation (Wire Arc Additive Manufacturing – WAAM). However, despite the great scientific groundwork, the composition, structure and properties of bimetallic composites produced by the WAAM method have not been sufficiently studied. The purpose of the presented work is to study the effect of WAAM technological parameters on the composition and structure of the layered bimetallic composite “Sv-08G2S – Sv-07Kh25N13”. Experimental samples for research were produced by the WAAM method at various printing strategies and specific energies. Studies of the microstructure of the sections and chemical analysis of various zones of the composite were carried out. It is shown that the WAAM modes and the surfacing strategy largely determine the structure and phase composition of the main layers and transition zones of the bimetallic composite. The structure of Sv-08G2S steel in the composite is represented by ferrite and ferrite-cementite mixture (perlite), and Sv-07Kh25N13 steel by various ratios of austenite, δ-ferrite, carbides and intermetallide phases. It has been established that the distribution of chemical elements in various sections of the steel Sv-08G2S included in the bimetallic composite is stable and does not depend on the parameters of WAAM surfacing for steel Sv-07Kh25N13. For steel Sv-07Kh25N13, the distribution of chemical elements significantly depends on the WAAM surfacing mode.The work was supported by the grant of the Russian Science Foundation No. 22-79-10204 “Development of scientific and technological foundations for the synthesis of WAAM-obtained layered polymetallic composite materials for operation in low-temperature conditions.”