Microstructure and Properties’ Evaluation of W18Cr4V Modified by Fe–Zr–Nb–N–B Nano‐Powder Inoculants

Abstract

High speed steel (HSS) is widely used in the production of high‐speed cutting tools and roll etc. Fe–Nb–Zr–N–B amorphous nanocrystalline powder inoculants are designed and prepared by melt and ball‐milling. The carbides in inoculants are easy to act as the nucleus of heterogeneous nucleation during the solidification of the HSS melt, which can refine the grain size of as‐cast HSS significantly. At the same time, it can further improve the morphology and distribution of carbides in the HSS matrix. The phase composition of rapid solidified Fe–Nb–Zr–N–B inoculants is analyzed using XRD and TEM. With the addition of Fe–Nb–Zr–N–B inoculant, the grain size of as‐cast HSS refined evidently, the Net thickness and dendritic spacing decrease obviously, simultaneously, the distribution of the carbides in HSS matrix is more homogeneous. That results lead to a significant improvement of the microstructure and mechanical properties of the HSS. The grain size of HSS in quench state decreases obviously after inoculation treatment with Fe–Nb–Zr–N–B. Meanwhile, the hardness and red hardness as well as the abrasion performance are improved obviously.