Influence of sliding frequency on reciprocating wear of mold steel with different microstructures

The wear resistance of a low alloy plastic mold steel has been studied under pin-on-flat reciprocating configuration against AISI 52100 steel pins, under variable sliding frequency. The as-received material (HTO; 33 HRC) was heat treated under variable conditions to obtain different microstructures and hardness (HT1, quenched 880 °C, 58 HRC; HT2, tempered 550 °C, 43.4 HRC; HT3, tempered 300 °C, 52 HRC; HT4, annealed, 26 HRC). Under low sliding frequency (1 Hz), no significant differences in the wear resistance of the different materials are observed. Only at 8 Hz, a relationship between hardness and wear resistance is found. The softer annealed material HT4 shows an increasing wear rate under increasing frequency, while the quenched steel HT1 gives the lowest wear at the highest frequency. Wear mechanisms have been studied from SEM and EDS observations. Only HT4 shows a transition from the abrasive and oxidative wear mechanisms found in all cases to an adhesive wear mechanism under the highest frequency.