Jason Shaw
MANE-6690 – Homework 4
Problem 1
When the load on the tool steel disk is low, the wear debris is mostly small particles or fully oxidized
particles that result from the sliding wear mechanism. As the load is increased, the temperature of the
material is elevated to a point that causes austenitization and subsequent martensite formation due to
self quenching. This process provides a much harder surface, thus accounting for the reduced wear.
Problem 2
The wear mechanism map of steel is shown below:
At low normalized pressure and low normalized velocities, the steel is in the ultra mild wear range. As
the normalized velocity and pressure is increased, the steel enters the delamination wear zone, which
includes the mild to severe wear transition. Severe oxidational wear is experienced at high normalized
velocities, and the steel begins to melt wear at higher normalized pressures.