Effect of volume fraction of (Cr, Fe)7C3 carbides on corrosion resistance of the Fe-Cr-C hardfacing alloys at Cr/C=6

In this investigation, three different chemical compositions of Fe-Cr-C alloys were fabricated on AISI 1010 steel substrates by gas tungsten arc welding (GTAW). The optical emission spectroscopy (OES), optical microscopy (OM), scanning electron microscopy (SEM), techniques and corrosion test were used for determining chemical composition studying the microstructure and corrosion behavior of the Fe-Cr-C alloys. The OM and SEM results show that the microstructure of these alloys consisted of (Cr,Fe)7C3 carbides with austenite, and by increasing of the carbon and chromium content in hardfacing alloys, the volume fraction of (Cr,Fe)7C3 carbides in microstructure was increased. The polarization curves of the corrosion tests show that the increase of the volume fraction of (Cr,Fe)7C3 carbides in the microstructure promotes the corrosion resistance of the Fe-Cr-C hardfacing alloys. The corrosion mechanism of the Fe-Cr-C hardfacing alloys was intergranular and galvanic corrosion