High Temperature Mechanical Properties of SAE EV11 Engine Valve Steel

Mechanical properties of EV11 engine exhaust valve steel have been determined for two different heat treatment conditions, corresponding to coarse and fine grained structure with different carbide content.

Testing has been performed at room temperature, 650, 750 and 850°C; the following information has been obtained:

• - hardness and tensile properties
• - creep rate dependence on stress and temperature.

The selection of engine valve material has been discussed on the basis of the above information type combined with existing models for fatigue phenomena.

The role of metallurgical variables has been examined with particular regard to creep resistance, the first indication being that creep rate is unaffected by carbide particles.