Assessment of the Influence of Microstructure on the Abrasive Wear Resistance of Cast Steels with Microadditions of Boron and Vanadium Using Principal Component and Cluster Analysis

The study presents the results of investigations concerning the influence of microstructure, in particular the fraction of martensite and bainite, on the abrasive wear resistance of alloy cast steels with microadditions of boron and vanadium. Two cast steels were subjected to various heat treatment routes to obtain distinct martensitic and bainitic microstructures. Microstructural characterisation was performed using light, scanning electron, and transmission electron microscopy. Abrasive wear resistance was assessed by means of a T-07 tribotester operating under three-body abrasion conditions. The test arrangement was based on the principles of the ASTM G65-16 dry sand/rubber wheel abrasion test. Loose electrocorundum was used as the abrasive material, and all experiments were conducted under a constant load of 44 N. The results showed that martensitic microstructures exhibited significantly higher abrasive wear resistance than bainitic microstructures. The formation of upper bainite reduced hardness and intensified micro-cutting and micro-ploughing mechanisms. However, lower bainite obtained by austempering at temperatures corresponding to those used for martensite tempering exhibited comparable or even superior tribological performance despite its lower hardness, indicating that abrasive wear resistance is governed not only by hardness but also by microstructural characteristics. Vanadium content had no significant effect on wear resistance under the applied test conditions. Multivariate statistical analyses confirmed that abrasive wear resistance depends not only on hardness but also on microstructural features.