A Study on Engine Valve and Seat Insert Wearing Depending on Speed Change

The minimization of valve and seat insert wear is a critical factor in the pursuit of engine performance improvement. In order to achieve this goal, we have developed a new simulator, which can generate and control high temperatures up to 900°C and various speeds up to 80Hz during motion, just like an actual engine. The wear simulator is considered to be a valid simulation of the engine valve and seat insert wear process with various speeds during engine activity.

The objective of this work focuses on the different degrees of wear from two different test speeds (10Hz & 25Hz). For this study, the temperature of the outer surface of the seat insert was controlled at 3 50°C, the cycle number was 2.1×10⁶, and the test load was 1960N. The wear depth and surface roughness were measured before and after the testing using a confocal laser scanner. It was found that a higher speed (25Hz) causes more wear than a lower speed (10Hz) under identical test conditions (temperature, cycle number and test load). In the wear mechanism, adhesive wear, shear strain and abrasive wear could be observed.