Study of Microstructure and Wear Resistance Fe-C-Nb Hardfaced Alloy on Mild Steel

In this Investigation ST37-2 plates were used and coated by graphite and different amount of ferroniobium mixture, GTAW in bead on plate carried out in constant heat input and dilution, result of chemical analysis shown that can be produced hardface layers with different amounts Nb in chemical composition (0.16% to 1.34%). Result of hardness test shown that with increased Niobium in chemical composition of hardface layers, Hardness increased and maximum value was gained in sample No4 with 1.34% Niobium, the metallographic test result shown that with increased Niobium in chemical composition, volume fraction of martensite in microstructure decreased and amount of Austenite and NbC carbides increased, also carbides morphology were changed from rod shapes in sample No1 (0.16% Niobium) to equiaxed in sample No4 (1.34% Niobium) and maximum wear resistance was gained in sample No4.