Abstract
The effect of porosity and worked layer on small fatigue crack propagation behavior was investigated for sintered steels. Reversed plane bending fatigue tests were conducted and small fatigue cracks were observed by means of plastic replica technique. It was found that worked layer inhibited fatigue crack initiation and crack growth. On the other hand, improvement of porosity had small effect on crack initiation, while crack arrest was remarkable in the low porosity sintered steels.
