The Effect of Carbon and Chromium Content on Microstructure and Wear Resistance of Fe-(6X)Cr-(X)C Hardfacing alloy Fabricated by GTAW on Mild Steel

In this investigation different series of Fe-Cr-C hardfacing alloys with the constant ratio of were fabricated by GTAW on AISI 00 mild steel substrates. OES method was used for determining chemical composition of surface layers while OM, SEM, XRD were used for studying the microstructure and phases characteristics, hardness test (Vickers macro hardness method) was also used to determine hardness of surface layers. The metallographic examination and XRD results indicated that all specimens microstructure consisted of austenite and chromium-iron carbides, (Cr,Fe)7C, moreover by increasing of carbon and chromium content in hardface layers, the volume fraction of (Cr,Fe)7C increased while it caused to decreasing the austenite volume fraction and increasing hardness of the top surface layers. In addition wear Test result Shows that with increasing the chromium and carbon content in hypoeutectic alloys, the wear resistance increase, study of SEM of worn surface determined that wear mechanism of hypo eutectic alloys was micro ploughing, and in eutectic and hyper eutectic were microcutting and micro cracking.