Influence mechanism of Y addition on microstructure, adsorbability, mechanical properties of as-cast high speed steel

To improve the mechanical properties of high speed steels (HSSs), different contents of rare earth Y (0, 0.047, 0.096, 0.229, and 0.310 (wt.%)) are added, and the microstructure and mechanical properties of as-cast HSSs are systematically studied. The results show that the phases of HSSs are mainly composed of alpha-Fe, MC, M2C, and M6C (M = Fe, V, Cr, etc.). The Y element is primarily distributed at the interface between carbide and matrix. The morphology of carbide changes remarkedly with the increased Y content, i.e. the shape factor K of carbide in-creases from 0.3154 to 0.4028. Moreover, as the Y content increases from 0 wt% to 0.229 wt%, the strength, elongation and impact toughness of HSSs are improved from 516.7 MPa, 0.29% and 3.8 J to 820.9 MPa, 0.47% and 5.2 J, respectively. This provides a new idea for the design and application of HSSs, and has a practical reference value for the development of other wear-resistant materials.