The effect of arc current on microstructural and mechanical properties of nickel hardfaced deposits created using PTA processes

Abstract

PTA hardfacing was carried out on 316 LN austenitic stainless-steel plates with dimensions of 60 mm x 50 mm x 12 mm, and Colmonoy 5 powder was used in this research work. The austenitic stainless-steel plate was heated to 400 degree Celsius in order to avoid breaking. In order to avoid cracking, it was allowed to cool gently in vermiculite powder after hardfacing. For the creation of four unique hardfaced deposits, four different arc currents were used. Current ranging from 120A to 150A were utilized in the experiments. The travel speed, powder feed rate, standoff distance, and torch oscillation width were all kept at the same levels as they had been before. As a result of this investigation, it has been discovered that the hardfaced deposit’s microstructure is dominated by the Ni phase and an interdendritic mixture (eutectic) of Ni and nickel-rich borides in the interdendritic zone. In addition, these studies revealed the presence of chromium-containing carbides and borides in a nickel matrix, which was previously unknown. The hardness of deposits (Colmonoy 5) was found to be higher than that of the surrounding substrate.