Effects of Elasticity and Compactness of Graphite on the Fatigue Strength of Spheroidal Graphite Cast Iron Based on Successive Surface Observations

• Published in: Transactions of the Japan Society of Mechanical Engineers Series A Vol. 58; no. 554; pp. 1779 - 1784
• Main Authors: NISITANI, Hironobu, NAKAE, Hiroshi, MINAMI, Kazuhiro
• Format: Journal Article
• Language: English; Japanese
• Published: The Japan Society of Mechanical Engineers 1992
• Subjects: Compactness; Elasticity; Fatigue; Notch; Spheroidal Graphite Cast Iron; Successive Observations
• ISSN: 0387-5008; 1884-8338
• DOI: 10.1299/kikaia.58.1779

In this paper, rotating bending fatigue tests of two kinds of spheroidal graphite cast iron were carried out in order to clarify the effects of elasticity and compactness of graphite on the fatigue strength of the two cast iron samples. One is as-received cast iron whose graphites are compressed by the matrix and the other is cast iron annealed at 550°C whose graphites exist more loosely. The crack initiation limit of the as-received material is about 10% higher than that of the annealed material in the plain and notched specimens. The effects were discussed through the behaviour of the microcrack, based on successive observations using the plastic replica method.