ANISOTROPY OF FATIGUE CRACK PROPAGATION IN HOT ROLLED BANDED STEEL PLATE.
Abstract
The anisotropy of fatigue crack propagation in hot rolled steel plate was studied for three orientations relative to the rolling direction, viz., crack arrester, crack divider and short transverse. By controlling the heat treatment it was possible to modify the banded pearlite-ferrite microstructure to develop the following structures: pearlite-ferrite (homogenized), martensite (tempered)-ferrite (banded) and martensite (tempered)-ferrite (homogenized). These structures exhibited a range of mechanical properties, with the tensile strength varying from 70 to 200 ksi and the yield strength from 50 to 150 ksi. The fatigue crack growth rate data were interpreted in fracture mechanics concepts. The dependence of crack growth rate on stress intensity factor was shown to be sensitive to the microconstituents present and their orientation relative to the fracture plane and direction. Generally, crack growth rate dependence on stress intensity range increased as the material toughness decreased and when the fibering was oriented parallel to the fracture plane and direction. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1969
- Accession Number
- AD0695656
Entities
People
- Francis A. Heiser