# Comparison of Abrasive Wear Resistance of Hardox Steel and Hadfield Cast Steel
## 3 Results
### Abrasive Wear Resistance Tests  
Abrasive wear tests showed that high-manganese steels (both GX120 MnCr17-2 and L120G13T), despite their lower hardness, exhibit wear resistance comparable to Hardox 600 steel (Figure 5). The value of the coefficient \(k_{b}\) is equal to 1.33 (\(\pm\)0.03) and 1.32 (\(\pm\)0.01), respectively, for Hadfield steel (sample 2, designation L120G13T) and cast steel with higher chromium content (sample 1, designation GX120 MnCr17-2). However, for Hardox 600 steel, the value of the coefficient \(k_{b}\) is 1.29 (\(\pm\)0.02). A slightly higher value was obtained for Hardox Extreme steel (\(k_{b}\) = 1.39 \(\pm\) 0.02). Moreover, among Hardox steels, the relationship of hardness and wear resistance shows a linear correlation with the value of the coefficient \(k_{b}\) equal to 0.98 \(\pm\) 0.03 and 1.14 \(\pm\) 0.03, respectively, for Hardox 450 and Hardox 500 steels. Analysis of the surfaces of the tested materials indicated the presence of different wear mechanisms (Figure 6). In the case of high-manganese steels, the main observed wear mechanism was microploughing. There were also visible traces of impacted abrasive particles that result in occurrence of tear-outs of material in a direction disoriented from the movement of abrasive (marked as cavities). Moreover, on their edges, ridges (gouges) of plastically deformed material were present. In the case of martensitic steels, the severity of the intense changes on the surface decreased as the hardness of the material increased. The main wear mechanism of Hardox 450 and 500 steels was microploughing, plastic deformation and the breaking off of larger fragments of material, resulting in the occurrence of cavities. The formed plastic deformations were extensive and  
Figure 5: The value of the coefficient \(k_{b}\) and the results of hardness measurements of the analyzed metallic materials. C45 (N)—C45 steel in as-normalized condition with a hardness of 220 HBW. to the direction of abrasive movement. The presence of pits and chips on the edges of scratches, caused by the formation of microcracks and their propagation, was also visible. Similar traces could be observed in Hardox 600 and Hardox Extreme steels, but the width of the plastic deformations, grooves, breakouts and scratches were smaller. Moreover, the proportion of wear by microploughing decreased, and the material was mainly worn by microcutting. It should be noted that, according to the analysis of microstructural changes in the subsurface layers of the samples subjected to wear tests (Figure 7), high-manganese steels had the greatest change in profile height, which could be up to 9 \(\upmu\)m. Their surfaces were smooth and only locally sharply defined pits could be observed. In the case of Hardox 450  
Figure 6: Surfaces subjected to wear testing: (**a**) sample 1 (GX120 MnCr17-2); (**b**) sample 2 (L120G13T); (**c**) Hardox 450; (**d**) Hardox 500; (**e**) Hardox 600; (**f**) Hardox Extreme. Electron microscopy, unetched. and Hardox 500 steels, the deformation of the microstructure under the influence of the movement of abrasive grains under pressure was characteristic. Smoothly finished material breakouts and grooves could also be observed. Deformation of martensitic microstructure is also relevant to Hardox 600 steel. However, the presence of sharply ended breakouts indicated an increased contribution of microcutting to the wear mechanisms taking place. Moreover, the resulting pits were narrower and shallower compared to Hardox 450 and 500 steels. In the case of Hardox Extreme steels, the texture was less favoured and oriented (directed). The resulting pits were shallower compared to the other steels. The smooth surface was indicative of the uniform abrasion of the surface as a result of microcutting.