Effectiveness of metal powder additions for martensitic hardfacing alloy on its wear properties

Abstract

Selecting welding consumables to get satisfactory results in hard facing weld repair jobs at a low cost is an important consideration. The standard martensitic welding electrodes used for hardfacing are expensive, so an investigation into finding suitable substitutes is a worthwhile activity. The objective of this study was to analyze the hardfacing deposits on using a low carbon steel welding electrode with metal powders added to the weld pool. Four different samples were hardfaced applying a submerged arc welding setup with constant heat input. Single and three layers of hardfacing samples were welded using a standard martensitic electrode and compared to using low carbon steel electrodes with added metal powders. An optical emission spectrometer was used to obtain the chemical compositions of welded metal layers. A scanning electron microscope was used to characterize the metallurgical structures of deposits. SEM images of worn surfaces were also obtained. Microhardnessand abrasive testing were used to examine the mechanical properties of the hardfaced surfaces. The results showed that martensitic microstructures were obtained in the hardfaced deposits using a low carbon steel welding electrode with added metal powders. However, hardness and abrasive wear resistance of both single and three layers of hardfacing using low carbon steel welding electrode with added metal powder were below those achieved by welding with a standard martensitic electrode.