Effect of austempering temperature on cavitation behaviour of unalloyed ADI material

Journal Article · Thu Aug 15 04:00:00 EDT 2013 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2013.05.005· OSTI ID:22285067

Dojcinovic, Marina ^[1]; Eric, Olivera ^[2]; Rajnovic, Dragan; Sidjanin, Leposava ^[3]; Balos, Sebastian ^[3]

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1. University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade (Serbia)
2. Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade (Serbia)
3. Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia)

This paper provides an in-depth study and description of cavitation damage and microstructural changes in two types of unalloyed austempered ductile iron (ADI). ADI materials used were austempered at 300 and 400 °C having ausferrite microstructure with 16 and 31.4% of retained austenite, respectively. Metallographic examination was carried out to study the morphology of their cavitation-damaged surfaces. Cavitation damage was initiated at graphite nodules as well as in the interface between a graphite nodule and an ausferrite matrix. Furthermore, microcracking and ferrite/retained austenite morphology were proved to be of great importance for cavitation resistance. Mass loss rate revealed that ADI austempered at 400 °C has a higher cavitation resistance in water than ADI austempered at 300 °C. A higher amount of retained austenite in ADI austempered at 400 °C played an important role in increasing cavitation resistance. The good cavitation behaviour of ADI austempered at 400 °C was due to the matrix hardening by stress assisted phase transformation of retained austenite into martensite (SATRAM) phenomenon, as shown by X-ray diffraction analysis. - Highlights: • Cavitation rate of two ADI materials was tested. • ADI material with a lower hardness has had a lower cavitation rate. • The main reason is microstructural transformations during cavitation. • SATRAM phenomenon increases cavitation resistance.

• OSTI ID: 22285067
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 82; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AUSTENITE
CAVITATION
FERRITE
GRAPHITE
MARTENSITE
MICROSTRUCTURE
PHASE TRANSFORMATIONS
STELLAR WINDS
X-RAY DIFFRACTION