Erosion characteristics of ductile iron with various matrix structures

Abstract

Erosive wear tests were performed on austempered ductile iron (ADI), ferritic ductile iron (FDI) and pearlitic ductile iron (PDI) using a shot blast machine. Erosion damage was measured by the removed material volume at impact angles between 10° and 90°. The surface metal flow in vertical sections was also observed. The mechanism of erosive wear, the effect of impact angles, and differences in wear features of specimens were discussed. Experiment showed that, after an initial stage, the eroded volume increases almost linearly with blasting time in ADI, FDI and PDI. The erosion rate for ADI is about 1 10 – 1 25 of that for FDI and PDI. The surface hardness of eroded ADI specimens increased from the initial HV350 to HV700 after 600 s of blasting. The amount of retained austenite was measured as about 40% before the test, but decreased to about 3–5% by transformation of austenite to martensite, hardening the surface and lowering the erosion rate. It was shown that ADI has excellent erosion resistance and it is expected to find wide applications as a wear-resistant material.