To Study the Effect of Austempering Temperature on Fracture Behaviour of Ni-Mo Austempered Ductile Iron (ADI)

Abstract

Austempered Ductile Iron (ADI) can be as twice as strong as standard spheroidal iron at the same level of toughness. It responds to work-hardening surface treatments and exhibits excellent fatigue and wear property. There is extensive work done on the fracture of steel with ferrite or/and austenite structure, but little on fracture behaviour of ADI whose microstructure also comprises austenite and ferrite but with graphite nodules in the matrix. The present work is aimed in this direction. The fracture behavior of Ni-Mo ADI is studied. It is found that the crack always originates from graphite nodules and the matrix affects the propagation path.