Assistant Professor, University of California at San Diego, San Diego, CA
New Jersey Zinc Professor, and Chairman, Lehigh University, Bethlehem, PA
Research Associate, E. I. du Pont de Nemours and Company, Inc., Engineering Technology Laboratory, Experimental Station, Wilmington, DE
(Received 9 December 1987; accepted 23 January 1989)
The fracture behavior of modified AISI 1140 resulfurized steel containing manganese (1.05 to 1.25%) and sulfur (0.16 to 0.23%) has been studied under controlled fast fracture and fatigue fracture conditions. “C”-shaped ring samples were machined from tubes hammer forged at 700°C by the GFM process (Gesellschaft für Fertigungstechnik und Maschinenbau [AG] manufactured in Steyr, Austria) so as to develop a highly fibered (axial) microstructure. The microstructure of the material was evaluated and compared with the fracture surface morphology as a function of loading history. It was determined that the MnS inclusion stringers were encapsulated within the ferrite phase and that static fracture progressed along the stringer-ferrite interface. Conversely, fatigue cracks as evidenced by the presence of fatigue striations propagated mainly within the ferrite phase.
Paper ID: JTE11127J