Abstract
A Study has been made on the fracture behaviour of sintered carbon steels under static tensile stress. The specimens containing 0.2, 0.4, and 0.8 mass% carbon were made from atomized iron powders of different particle size (+145, -145+250, and -250 mesh).
The microscopic fracture appearance of sintered carbon steel was ductile fracture in necks between particles, and depended on the microstructure of matrices. The apparent porosity in projected fracture surface was much higher than the value predicted by the porosity of specimen.
Scanning electron microscopic examination of fracture surfaces showed an evidence of six distinct modes of fracture; i.e. (a) tear ridge, (b) dimple, (c) lamellar dimple or midrib dimple, (d) tearing off of cementite plate, (e) cleavage with inter phase separation, and (f) cleavage.
The apparent porosity in projected fracture surface reflects these fracture modes, therefore gives an information on the fracture behaviour of sintered steels.
