Microstructure, thermal, and mechanical characterization of rapidly solidified high strength Fe_84.3Cr_4.3Mo_4.6V_2.2C_4.6

Systematic microstructural and mechanical investigations of the Fe_84.3Cr_4.3Mo_4.6V_2.2C_4.6 alloy cast under special manufacturing conditions in the as-cast state and after specific heat treatment are presented to point out that the special manufacturing of the alloy led to high compression strength (up to 4680 MPa) combined with large fracture strain (about 20%) already in the as-cast state. One select chemical composition of the alloy, which was mentioned previously [Kühn et al., Appl. Phys. Lett.90, 261901 (2007)] enhanced mechanical properties already in the as-cast state. Furthermore, that composition is comparable to commercial high-speed steel. By the special manufacturing used, a high purity of elements and a high cooling rate, which led to a microstructure similar to a composite-like material, composed of dendritic area (martensite, bainite, and ferrite) and interdendritic area (e.g., complex carbides). The presented article demonstrates an alloy that exhibits already in the as-cast state high fracture strength and large ductility. Furthermore, these outstanding mechanical properties remain unchanged after heating up to 873 K.