Effect of Ti and Nb on the microstructure and mechanical properties of cast high speed steel

In the present study the comparison of effects of Ti and Nb in cast M7 high speed steel were investigated. The microstructure, the shape and volume pe rcentages of microcomponents were studied using light end electron microsco pe with the aid of EDX and WDX analyzers. Bend and impact properties or wel l or hardness and hot hardness of Ti-alloyed and Nb-alloyed M7 steel were d etermined so that the effects of these two elements on the mechanical prope rties could be determined. The results show that Ti has the stronger effect s than Nb on the microstructure modification and can produces more homogene ous cast structure. It is also found that, at the presence of Ti the mechan ical properties ore higher than those of Nb.