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It has been evaluated the relationship between the microstructure and three-body abrasive wear behavior of high-chromium (18 and 27 mass % Cr) based (3 mass % each of V, Mo, W, and Co) multicomponent white cast iron materials (high-Cr MWCIs). It was also compared to MWCI to determine the service life of the materials. The results indicate that the microstructure of the material is composed of mainly martensite matrix and different types of precipitated carbides. The wear resistances of both the high-Cr MWCIs are higher than MWCI owing to the higher hardness (4–18% increment in hardness), although they contain fewer carbide types. The carbide volume fraction of high-Cr MWCI increases with increase in the Cr content, but the hardness decreases, leading to a reduction in wear resistance. This is because the transition metal significantly consumes C atoms to form more eutectic carbides during solidification, which is exacerbated by the depletion of C in the matrix during heat treatment to form coarser secondary carbides. This means that increasing the addition of Cr does not always lead to an increase in the hardness or wear resistance of the material. In addition, the wear resistance of 27Cr MWCI after tempering (wear rate: 8.80 × 10−5 g/m) is higher than that after quenching (wear rate: 9.25 × 10−5 g/m) owing to the increase in the fracture toughness of M7C3 carbide. This is contrary to the case of 18Cr-MWCI; the wear resistance after tempering (wear rate: 5.29 × 10−5 g/m) is worse than that after quenching (wear rate: 5.11 × 10−5 g/m) owing to the reduction in hardness as a stress-relieving effect.

Since it is well known in the literature that transition metals can form extremely hard carbides and effectively strengthen a material’s matrix, recently, some of them, such as V, Nb, Cr, Mo, and W, have been simultaneously added to cast iron. In addition, it is common to add Co to cast iron to strengthen the material’s matrix. However, the wear resistance of cast iron can also be considerably affected by the addition of C, which is rarely discussed in the literature by the experts. Therefore, the effect of C content (1.0; 1.5; 2.0 wt.%) on the abrasive wear behavior of 5 wt.% V/Nb, Cr, Mo, W, and Co alloys was investigated in this study. An evaluation was conducted using a rubber wheel abrasion testing machine in accordance with ASTM G65 with silica sand (1100 HV; 300 μm) as abrasive particles. The results show that plural carbides (MC, M2C, and M7C3) precipitated on the microstructure of the material, which is not unlike the behavior of other types of carbides as the quantity of C increases. The hardness and wear resistance properties of 5V-5Cr-5Mo-5W-5Co-Fe and 5Nb-5Cr-5Mo-5W-5Co-Fe multicomponent cast alloys increased as the quantity of C increased. However, we observed no significant difference in the hardness between the two materials with the same C additions, while 5Nb presented better wear resistance properties compared to the 5V sample due to the larger size of NbC compared to VC. Therefore, it can be determined that, in this study, the size of the carbide plays a more important role than its volume fraction and hardness.

The need for better wear-resistant materials to reduce cost and save the environment is noteworthy. The striking wear resistance of high chromium white cast iron (HCCI) has made it industry’s predominant choice. The three-body abrasive wear resistance performance of HCCI was investigated based on combined Ti and C. The Ti and C content varied in different percentages. The addition of Ti resulted in refined M7C3 carbides and TiC crystallization. The hardness was significantly affected by the addition of Ti. The increment in Ti content resulted in a decrease in the hardness, leading to a higher wear rate. However, the individual contribution of C led to higher hardness and, hence, better wear resistance, which is contrary to Ti. Out of the three specimens with 3, 3.5, and 4 wt.% C content, the 4 wt.% C series showed the highest hardness but the lowest wear rate and depth. This study found that the combination of a lower percentage of Ti with a higher percentage of C in HCCI can have a worthwhile result in abrasive wear.

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