RT Generic
T1 Evaluation of impact and fatigue properties on austempered ductile iron
A1 Arias Fernández, Sergio
A2 Chalmers University of Technology, 
AB Austempered Ductile Iron (ADI) proved to be an excellent material as it possessesattractive properties: high strength, ductility and toughness are combined with good wearresistance and machinability. In this work impact and the fatigue properties have beenevaluated for low alloyed Austempered Ductile Iron. To do this, Charpy-type impact test foraustempered ductile iron was performed by the standard ASTM A 327M and FatigueCrack Growth Rates (FCGR) were measured by the standard ASTM E 647. It was foundthat impact energy is related with the morphology of the graphite nodules in themicrostructure. In particular, the impact energy increases when the nodularity and thenodule count increase, and the nodule size decreases. A clear relation with the amount ofretained austenite wasn’t found. For the fatigue properties it was found that these wererelated with the morphology of microstructure (graphite nodules, amount of retainedaustenite and its carbon content). However, it was observed that the the crack initiationwas mainly affected by the presence of defects as porosity or carbides. When thepreferential crack path was observed between two neighboring nodules, the crack growthrate increased when two graphite nodules were closer. The growth of the crack dependson the orientation of the ferrite laths, but, in this work, it was observed that the crack pathprobably takes place along the austenite/ferrite interface. Furthermore, it was found thatthe likelihood of crack formation, facilitated by decohesion of the graphite nodules,increased with nodule size.
YR 2009
FD 2009
LK https://hdl.handle.net/10016/8372
UL https://hdl.handle.net/10016/8372
LA eng
DS e-Archivo
RD 1 may. 2024