Effect of Chromium on Solidification Microstructure and Wear Property of High Vanadium Wear-resistant Alloy

The equilibrium solidified and the vertical section phase diagrams of Fe-C pseudo-binary were drawn with different chromium content (Fe-3.0%C-10.0%V-0.8%Si-0.8%Mn-X%Cr, X=2.0,5.0,10.0, mass fraction) by the Thermo-Calc software. The effect of chromium on the phase diagrams and solidification microstructure was investigated by OM, SEM, EDS, XRD, DSC and wear resistance test. The results show that the changes of eutectic transition points and phase region area are tiny with the increase of chromium content. The calculated temperatures of precipitated phase are close to the DSC results. The solidification microstructure is composed with α-Fe, MC, and M7C3. Chromium is mainly distributed in α-Fe and M7C3 carbides. With the increase of chromium, the amount of MC decreases and the amount of M7C3 increases; the α-Fe has no change. The hardness of the cast alloy increases with the increase of chromium content, and the maximum value reaches to 67.0HRC when chromium content is 10.0%. The wear loss is about 15.6mg when the chromium content is 5.0%, the wear resistance is the best.