Age Strengthening of Gray Cast Iron: Kinetics, Mechanical Property Effects

Abstract

Previous work by Nicola and Richards (Nicola, 1999) has demonstrated that there is statistically significant age strengthening in most gray cast iron alloys. Differential scanning calorimetry studies have revealed two significant exothermic reaction peaks in fully aged gray iron specimens. Heating to a temperature above 250 ░C does not produce a significant change in tensile strength whereas heating above the second exothermic peak lowers the tensile strength proportionally with the original age strengthening. It is further shown that the strengthening effect returns upon re-aging. Precision hardness measurements have revealed that Brinell hardness also increases with age strengthening; however, not as much as the tensile strength, which makes the tensile-strength-to-Brinell-hardness ratio increase with aging time.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Age Strengthening; Exothermic Reaction Peaks; Gray Cast Iron Alloys; Kinetics

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2003 American Foundry Society (AFS), All rights reserved.

Publication Date

01 Jan 2003

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