Abrasion resistance characterization of low alloy construction steels: A comparison between three different scratch test protocols

In the present work, three different scratch tests are compared on their ability to rank the abrasion resistance of low alloy steels for industrial applications where the abrasion play a key role, e.g., in earthmoving, agricultural and mining equipment. The first test involves single pass scratching of pristine surfaces with a relatively large rigid indenter. The second test involves multi-pass scratching along a fixed track using the same large indenter. The third test involves the creation of a multi-pass scratch track using the same large indenter followed by final scratching of the abrasion track with a sharp indenter, i.e., Multi-Pass Dual Indenter (MPDI) scratch test. The three test protocols activate different abrasion mechanisms. Five low alloy construction steel grades with different strain hardening capabilities, i.e., Interstitial-free Ferritic steel (IF steel), Fully Martensitic steel (FM steel), Dual Phase steel (DP steel), Quench Partitioning steel (Q&P steel) and TWining Induced Plasticity steel (TWIP steel), are used. The results show that for both single (large) indenter scratch test protocols, the scratch depths always increase with indenter load and the failure mechanism is pure ploughing except for the IF steel due to the nature of softness. While for the dual-indenter scratch test, the scratch depth is a more complex function of the load applied during creation of the work hardened surface layer. The conventional scratch test protocols cannot well reveal micro-cracks and defect in (sub) surface and cannot well reflect the real response of strain hardening of steels. However, the MPDI test can distinguish between different steels with different initial hardness and different strain hardening behaviour and reveal the damage and, equally important, can indicate how average loading conditions may affect the relative abrasion resistance of construction steels during steady state conditions.