TITLE:
Microstructure, Mechanical Properties, Toughness, Wear Characteristics and Fracture Phenomena of Austenitised and Austempered Low-Alloyed Ductile Iron
AUTHORS:
Nabil Fatahalla, Osama Hussein
KEYWORDS:
Austempered Ductile Iron, Low-Alloyed Ductile Iron, Tensile Properties, Wear Characteristics, Microstructure, Hardness
JOURNAL NAME:
Open Access Library Journal,
Vol.2 No.1,
January
30,
2015
ABSTRACT: Conventional ductile iron (DI) and austempered ductile iron (ADI) alloys
were successfully produced. The alloying elements—Ni, Mo, Cr and Mn were added
to get as-cast low-alloyed ductile iron (LADI) followed by austempering heat
treatment. Hardness was measured for all investigated alloys. A hardness conversion
table was deduced for irons investigated. Highest values of calculated quality
index (QI) were for ADI alloys implying higher material performance. Impact
energy values were attributed to microstructure and tensile properties. Wear
characteristics of selected ADI alloys showed comparable values with LADI. Micro-hardness
values were used to identify the micro-constituents and the work-hardened
layers. Fracture modes were revealed and fracture surface observations were
done by SEM. Due to higher toughness and QI, and cheap price, it is suggested
that rolling mills may be produced from ADI, specially heat-treated instead of
LADI.