Fracture and fatigue behavior of sintered steel at elevated temperatures: Part I. Fracture toughness

This study investigates fracture resistance of a sintered steel in the temp erature range from 25 degrees C to 300 degrees C. The temperature-dependent fracture resistance is experimentally determined by fracture toughness tes ts. The fracture toughness, K-1C, decreases from 28.8 at room temperature t o 23 MPa root m at 300 degrees C. The finite element analysis shows an insi ght of the rationale of using K-1C as the parameter to characterize the fra cture resistance of porous sintered steel in which the stress intensity (K) field has been severely distorted at the porous crack tip. The analysis in dicates that crack onset of sintered steel is controlled by a critical stre ss mechanism.