Friction and Wear Behaviors of HT200 Sliding Against QT600 Under Flame Ablation Environment

Abstract

Under lean lubrication conditions, as well as during cold and hot starts of the engine, the cylinder liner and piston rings experience significant wear, which affects the engine's efficiency and lifespan. The dry friction and wear behaviors of HT200 encountered with QT600 under flame ablation environment, high-temperature environment, and room temperature are studied using a laboratory-developed tribometer in this study. The changes in the coefficient of friction (COF), depth of the worn scars, the surface morphologies of the worn scars, and the wear mechanisms are analyzed. Experiment results show that the coefficient of friction significantly increases under flame ablation and high-temperature environments. The coefficient of friction under room temperature is around 0.25, and the COF under a high-temperature environment and flame ablation environment is in the range of 0.5–0.6. Meanwhile, under a flame ablation environment, the wear volume of the HT200 specimen is significantly higher than that at room temperature, but it is lower than that under a high-temperature environment. The wear volumes of the HT200 specimen under flame ablation environment, high-temperature environment, and room temperature are around 5.0 × 108 μm3, 9.0 × 108 μm3, and 3.0 × 108 μm3. Due to the effect of oxide consumption of the flame ablation, the formation and breakage of the oxide layer under the flame ablation environment occur less frequently than that under a high-temperature environment. Under a flame ablation environment, abrasive wear is the primary wear mechanism, along with the formation and fracture of the incomplete oxide layer, spalling, and adhesion of wear debris for the HT200 specimen.