In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.
In the present work, the effect of Ti addition on microstructure and properties of high speed steel (HSS) used for rolls was investigated utilizing optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy spectrum analysis. The results indicated that as-cast microstructure of the HSS roll is mainly composed of MC, M2C and M7C3 eutectic carbides and metallic matrix consishing of a mixture of martensite, austenite, and pearlite. The carbides are connected or placed next to each other to form a network along grain boundaries. The addition of 0.5 wt.-% Ti leads to a great change in the morphology, size and distribution of carbides. The carbide network tends to break, and all carbides are refined and distributed homogeneously in the matrix. After normalizing treatment at 1050 °C, the carbides in the Ti containing HSS roll transform into granular or nodular distribution. The mechanical properties, thermal fatigue, and wear resistance of Ti containing HSS roll are more excellent than that of the HSS roll without titanium.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.