Quenching and Partitioning Process in Ductile Cast Irons

Abstract

A commercial ductile iron alloy was submitted to Quenching and Partitioning (Q&P) process. Samples were austenitized at 900ºC for two hours, quenched at 170ºC and held at this temperature for 2 minutes and finally were re-heated in temperatures between 300 and 450ºC in time intervals between 2 and 180 minutes. The microstructure evaluation was performed with SEM and X-ray diffraction and mechanical properties were measured using uniaxial tensile tests and Charpy tests. In general, the Q&P process is suitable to achieve large fractions of retained austenite in ductile cast irons. The combination of properties thus obtained is very interesting from the engineering point of view, and if the elongation can be increased will provide an alternative to the austempered ductile irons.