In this work, a novel TiAlMoNbW high-entropy alloy (HEA) film and its corresponding nitrid (HEN) film were deposited on CSS-42L bearing steel by magnetron sputtering technology. The microstructure, microhardness, wear resistance, and corrosion resistance of the coated CSS-42L steel were systematically investigated. With the introduction of nitrogen, the crystal structure of TiAlMoNbW HEA film transformed from BCC into FCC. The microstructure of the deposited film became denser and was accompanied by lower surface roughness. The hardness of the nitride film was further increased from 11.43 to 25.7 GPa due to the formation of saturated metal nitride phases and the solid-solution strengthening of various elements. The tribological results showed that both TiAlMoNbW HEA and HEN films with excellent mechanical properties could improve the wear resistance of CSS-42L substrate, especially for the nitrid film, the mechanical properties of the film are significantly improved, resulting in a substantial reduction in the friction coefficient of about 22% and the wear rate of nearly 79%. In the electrochemical tests, both the TiAlMoNbW HEA and HEN-coated samples exhibited lower current densities and corrosion rates in 3.5 wt.% NaCl and 1 mol/L H₂SO₄ solutions. It was also noticed that the TiAlMoNbW nitrid film possessed a superior corrosion protection effect for CSS-42L steel.

Ferro-coke, as a new burden of blast furnace (BF), can not only greatly reduce the energy consumption and CO₂ emission, but also promote the resource utilization by using the low-quality iron ore and low-grade coal. However, the strength of ferro-coke decreased with the increasing amount of iron ore powder. In order to maintain the strength of ferro-coke while increasing the amount of iron ore powder, it is necessary to add binder during the coking process to enhance the strength of ferro-coke. In this paper, phenolic resin, silicon metal powder, corn starch, and coal tar pitch were used as binder for the fabrication of ferro-coke. I-type drum machine (I 600), scanning electron microscope (SEM), and X-ray diffraction (XRD) were applied to test the crushing strength, morphology, and microcrystalline structure of the ferro-coke. The results showed that the increasing amount of iron ore powder resulted in lower crushing strength, higher porosity, and the worse macroscopic morphology of ferro-coke. When the amount of iron ore powder reached 40%, obvious cracks appeared on the surface of ferro-coke. When the amount of iron ore was 30%, the crushing strength of ferro-coke dropped to 18.15%. Among the four binders, coal tar pitch could significantly enhance the cold crushing strength of ferro-coke through decreasing the porosity of ferro-coke and improving the bonding effect between carbon matrix particles. In the case of the 10% coal tar pitch addition, the cold crushing strength of ferro-coke was increased from 18.15% to 76.41%; meanwhile, its hot compression strength during gasification improved by 100N.

For present and future advanced aerospace bearing applications, it is significant and necessary to improve the corrosion resistance of carburized CSS-42L steel. In this study, Cr films of about 1 μm in thickness were fabricated onto carburized CSS-42L bearing steel using a filtered cathodic vacuum arc deposition system. The corrosion behavior of carburized CSS-42L steel with Cr films was investigated. The Cr film was composed of nanocrystalline α–Cr. The electrochemical experimental results indicated that the current density had two orders of magnitude decrease and the corrosion potential evidently increased after Cr film deposition. The protective efficiency of this Cr film was as high as 99.7%. Nanocrystalline exhibits a higher corrosion resistance and enhances the modification effect of Cr film on carburized CSS-42L steel.