Investigation of variable-temperature wear characteristics of austenitic stainless steel coatings fabricated via laser energy deposition

The dissipation of frictional energy, particularly concerning material wear at various temperature ranges, requires further investigation. This study examines the variable-temperature friction and wear behaviors of austenitic stainless steel coatings prepared via laser cladding and remelting, simulating the operational conditions of heavy truck brake drums. The results indicate that graphite nodules in the cast iron matrix absorb and disperse stress during wear, exhibiting self-lubricating properties. This process reduces surface roughness and the coefficient of friction, decreases contact stress and shear stress, and effectively minimizes wear on the specimens and their tribo-pairs. Higher wear temperatures promote the oxidation of wear debris, forming a dense oxide layer, which results in lower friction coefficients and wear rates in the 275-525 degrees C range compared to the 25-275 degrees C range. Among the coated specimens, those processed with a lower remelting power of 1.6 kW and a higher speed of 40 mm/s exhibited the lowest dilution rate, highest hardness, and optimal H/E and H3/E2 values, demonstrating superior wear resistance in the 275-525 degrees C range. The oxide layer was most compact, with a thickness of 10.24 mu m, the lowest coefficient of friction (0.390), and the wear rate is the lowest, only 1.360 x 10-3 mm3/N & sdot;m, which is 46.66 % of the original coating and 29.41 % of the cast iron.