Abstract
The effect of crystallographic orientation on fatigue crack propagation was studied with an 18-8 stainless steel and a carbon steel by applying the etch pit technique to observe their fracture surfaces. There was no marked preferential orientation on the fracture surfaces of both materials in contrast with the aluminum alloy previously studied. This seems to suggest that complex slip systems are operating around the tip of fatigue crack of these materials. In the case of the stainless steel, the combination of {100} fracture surface and <110> crack propagation direction was somewhat preferred, and a few cleavage-like facets associated with brittle striation-like patterns were observed on fracture surfaces, the orientation of the facets being {111} which is said to be a cleavage plane or twinning plane of face centered cubic metals.
