Optimization of size of coherent κ’–nanocarbides for achieving superior abrasion and wear resistance in a lightweight steel

The effects of heterogeneous grain size distribution and coherent L'1 2 κ–carbide size on the abrasion and wear behaviors in a lightweight steel were studied. The wear rate is observed to decline with decreasing average grain size and increasing coherent carbide size first, and then increase with further decreasing average grain size and increasing carbide size. The wear performance can be optimized by controlling the annealing/aging temperature and time. The observed superior wear performance can be attributed to the strong strain hardening induced during the wearing process, which is accommodated by the formations of nanograins, deformation twins, stacking faults and HCP phase at the surface. While the formations of these defects are suppressed for the samples with higher hardness. • Effects of grain/precipitation size on the wear behaviors of a steel were studied. • The lowest wear rate can be obtained at an intermediate grain/precipitation size. • Wear performance can be optimized by controlling annealing/aging temperature/time. • High strength induces strong resistance to plastic deformation but brittle fracture. • Superior wear performance is due to formation of nanograins and deformation twins.