Fracture test data for AAR cast steels were developed by the Case Western Reserve University from samples provided by RPI foundries. The data involved Dynamic Tear (DT), Drop Weight Test (NDT) and Charpy V properties. Steels of Grades B, C (N&T), C (Q&T) and E, from various sources, were included in the study. This report presents interpretative fracture mechanics analyses of the data. The analyses clearly define the railroad service temperatures for which these steels feature brittle, semiductile and ductile fracture properties. The fracture properties were also examined in relationship to metallurgical variables, such as composition and microstructures. It is shown that the fracture properties of Q&T steels of C and E grades are seriously degraded by the presence of pearlitic microstructures. The importance of adequate alloy content (hardenability) and effective quenching of castings is emphasized by these data. Recommendations are presented for (1) optimization of fracture properties and (2) for revised AAR specifications based on DT test reference to fracture mechanics criteria.

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 70 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00196453
  • Record Type: Publication
  • Report/Paper Numbers: AAR R-272 Proj H001 Res Rpt.
  • Files: TRIS
  • Created Date: Jul 31 1979 12:00AM