# Comparison of Abrasive Wear Resistance of Hardox Steel and Hadfield Cast Steel
## 4 Discussion
According to the results of the study presented in [52], Hardox 600 steel shows more favourable wear rates compared to Hardox Extreme steel in the presence of soil abrasive mass. The authors related the obtained results to the nature of the abrasive (its bonding and grain size) and the plastic deformation of the material with martensitic microstructure. Comparing the above results with those presented in the [53; 54; 55; 56], it should be pointed out that the correlation between hardness and wear resistance is not valid in the presence of an abrasive medium that poses a higher friction resistance, taking into account the medium abrasive soil mass (Figure 9). In this case, higher strength steels (Hardox Extreme, XAR 600, 38 GSA) havelower wear resistance compared to Brinar 400, Brinar 500, B27 or Creusabro 4800 steels. The medium soil, through its increased content of clay causing bonding of hard abrasive particles, has significantly reduced degrees of freedom of sand grains and acts with greater force on the tested surface [57,58]. Therefore, it can be concluded that wear resistance is strongly dependent on the type of abrasive, and in the case of a dry and loose medium, it is the hardness that shows a dominant influence on the obtained values. Figure 8: Coefficient of relative abrasion wear resistance \(k_{b}\) and results of hardness measurements of selected low-alloyed martensitic steels. HT-heat-treated. Based on the results presented in this paper and [33,41,43]. Figure 9: Resistance to abrasive wear in medium abrasive soil mass over the friction path of 20 km and results of hardness measurements of selected low-alloyed martensitic steels. HT-heat-treated. Based on [52,53,54,56]. In the case of high-manganese steel, the values of the coefficient \(k_{b}\) are similar to the results obtained for Hardox 600. As in the case of Creusabro steel, which is characterized by the presence of residual austenite [41], their high resistance is determined by the significant plastic deformation of the material and the predominant wear mechanism by microploughing. What is more, no significant differences in abrasive wear resistance were observed between the cast steel of basic chemical composition and the one with added chromium. It should be noted that, according to [59; 60], the above relationship can only be verified by increasing the clamping force of the countersample and extending the test time. In the analyzed case, when the applied load was 500 N, no clear differences in weight loss were observed between Mn12 and Mn12 CrN steel. Only as the test time was extended beyond 60 min and the pressure was increased to 1000 N, did the chromium-nitrogen steel begin to show more favourable wear rates due to a higher degree of strengthening of the subsurface layers. As it was shown, a rapid hardening effect that affects higher wear resistance could be obtained in the Mn12 CrN steel only under higher applied wear load. Hadfield steel is characterized by difficult weldability, and due to its tendency to coarse-graining and the lack of \(\alpha\) - \(\gamma\) transformation, it becomes practically impossible to implement heat treatment procedures aimed at fragmenting the structure. In this case, according to the results presented in the above paper, it is the high-strength boron martensitic steels that can provide an alternative, with similar wear resistance indices of Hadfield steel and Hardox 600 steel. The results obtained in this manuscript are consistent with the results of the work presented in [61], where the abrasive wear resistance of Hardox 450 steel was lower compared to MMA (medium-manganese austenitic) steel, during both sliding tribocorrosion and impact tribocorrosion tests.