Wear resistance of austempered grey iron under dry and wet conditions

Abstract

In this paper, a grey iron was submitted to low temperature isothermal heat treatment, austempering, in order to obtain austempered grey iron (AGI). Tensile strength, Brinell hardness and tribological properties were determined for the as-cast condition and for two austempering conditions. The tribological properties were evaluated by pin-on-disk testing in dry and wet environments. The results show that AGI exhibit better mechanical properties than the as-cast grey iron. Also, the mechanical properties of AGI improve as the isothermal heat treatment temperature decreases. The wear resistance of AGI is better than the wear resistance of as-cast grey iron in both dry and wet conditions. In dry conditions the wear resistance of AGI increases as the isothermal heat treatment temperature decreases. On the other hand, the wear resistance of AGI in wet conditions increases as the isothermal heat treatment temperature increased. The results are explained in terms of the microstructural differences found between the materials under evaluation.

Keywords

• Austempered grey iron
• Pin-on-disk
• Wear resistance
• Retained austenite
• Bainitic ferrite