DESTABILIZATION HEAT TREATMENT EFFECT ON EROSIVE WEAR CHARACTERISTICS OF HIGH CHROMIUM WHITE CAST IRON

Abstract

In the present investigation, erosive wear property of high chromium white cast irons (HCWI) is reported. HCWI were destabilized at two different temperatures of 955^oC and 1100°C, air cooling followed by tempering heat treatment at 400°C and 700°C at each destabilized temperature. Erosion damage was evaluated by the removed material mass at impact angle 45° and time of 10 Hours. The surface metal flow was observed. Surface morphology of each specimen was characterized with scanning electron microscopy (SEM). The effect of heat treatment on differences in wear features of specimens is discussed. Experiment showed that the erosion rate of specimen destabilized at 1100°C, air cooled followed by tempering at 400°C air cooling is the best than other treatments. The hardness of test surface by this treatment increased from the initial 57 to 58 HRC after 10 hour. It showed that austenite in the surface structure has been transformed to martensite , which hardened the surface. Similarly, work-hardening effect also occurred on specimen destabilized at 955°C, air cooled followed by tempering at 400^oC, air cooling to make its surface hardness increased to 59 HRC. It was shown that HCWI series heat treated at 955°C and 1100°C and tempered at 400°C have a very good erosive wear resistance and they are expected to find wide application as wear-resistant materials.