Effect of a ferritization heat treatment on the fracture toughness of ferritic spheroidal graphite cast iron

• Published in: Scripta materialia Vol. 42; no. 11; pp. 1047 - 1052
• Main Authors: Monchoux, J.P., Verdu, C., Fougeres, R.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 31-05-2000; Elsevier Science
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fatigue, corrosion fatigue, embrittlement, cracking, fracture and failure; Fatigue, embrittlement, and fracture; Fracture toughness; Materials science; Metals. Metallurgy; Physics; Spheroidal graphite cast iron; Treatment of materials and its effects on microstructure and properties; Spheroidal graphite cast iron; Fracture toughness; Fracture mechanics; Cast iron; Mechanical properties; SEM; Experimental study; Microstructure; Property processing relationship; Fractography; Heat treatments; Tenacity; Ductile cast iron
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/S1359-6462(00)00336-5

The aim of the present work was to clarify the role of a ferritization heat treatment on the fracture toughness of ferritic spheroidal graphite (SG) cast iron. Because of the high ductility of this material J sub 0.2/BL values were measured instead of K sub IC values. The crack length was indirectly measured by compliance variations induced by the reduction of the loaded area due to the crack growth. It was found that J sub 0.2/BL was increased by the ferritization heat treatment. This was explained by the disappearance of the pearlitic brittle phase. The weakening of the matrix-graphite interface after the heat treatment remains small and cannot compensate the former effect. The J sub 0.2/BL values measured were found approximately constant with the silicon content for the investigated materials (fully ferritic materials with Si varying from 2.60-3.25%).