Validation of Cr6Fe18Mo in tribaloy T-800 coating fabricated by induction heating assisted laser cladding

Abstract

Due to excellent performance of high-temperature wear and corrosion resistance, Tribaloy 800 (T800) alloy has been used in steel and petrochemical industry. Most scholars believe that it is Laves phase (Co3Mo2Si) that leads to high crack sensitivity of T-800 alloy. However, the formation of Laves phase is impossible under conditions where there is a tendency of phase separation. In this study, the phases composition of T-800 coatings fabricated by induction heating assisted laser cladding (IHLC) is discussed. Results show that T-800 coatings prepared by IHLC are consist of Cr6Fe18Mo5 and γ-Co supersaturated solid solution with many lattice defects. With the increase of preheating temperature, the fraction of Cr6Fe18Mo5 phase can be increased to be 51.19%, due to sufficient Fe element and maintaining time of temperature above 700 °C. The fraction of γ-Co with lattice defects and residual tensile stress in coating can be decreased with the increase of preheating temperature, which lead to a crack-free T-800 coating.