Journal of Materials Science and Engineering with Advanced TechnologyAuthor's: SUSIL K. PUTATUNDA and GOWTHAM A. BINGI
Pages: [39] - [70]
Received Date: Received October 7, 2011
Submitted by:
Austempered ductile cast iron (ADI) has emerged as a major engineering
material in recent years because of its many attractive properties. In
this investigation, the influence of a step-down austempering process
on the microstructure and mechanical properties including fracture
toughness of an unalloyed ductile cast iron was examined. Compact
tension and cylindrical tensile specimens were prepared from unalloyed
nodular cast iron as per ASTM standards and were subjected to
conventional as well as step-down austempering process at three
different austempering temperatures. The microstructure and mechanical
properties of these samples were evaluated and compared.
Test results show that both the step-down and conventional
austempering process resulted in very similar microstructure and
mechanical properties in unalloyed ADI. The fracture toughness of the
material was found to be influenced by both ferritic cell size
(d) and the austenitic carbon 
ferrite, austenite, austempered ductile cast iron (ADI), fracture toughness, microstructure, step-down, mechanical properties.
