Endurance limit design of spheroidal graphite cast iron components based on natural defects

G Marquis*, R Rabb, L Siivonen

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Abstract

Cast irons are used extensively in the production of large diesel engines for power generation or oceangoing ships. One current trend is to replace grey iron with spheroidal graphite (SG) iron for fatigue critical components. In order to take advantage of the higher fatigue strength of SG iron and ensure the reliability of a design; better understanding of the typical defects for these large castings and the relationship between these defects and the endurance limit fatigue strength have been studied; Testing included uniaxial constant amplitude, constant amplitude torsion, and simple variable amplitude loading sequences in the long-life regime. Defects in several thick wall castings have been statistically evaluated. A fracture mechanics based model involving matrix hardness and root area successfully related the defect size to-the experimentally observed fatigue limit. For ferritic-pearlitic SG iron, the hardness of the tougher pearlite phase was used in the model; The model also correlated the torsion and tension endurance limits, Endurance limit as a function of mean stress is presented in the form of Haigh diagrams.

Original languageEnglish
Title of host publicationFATIGUE CRACK GROWTH THRESHOLDS, ENDURANCE LIMITS, AND DESIGN
EditorsJC Newman, RS Piascik
PublisherAMERICAN SOCIETY FOR TESTING AND MATERIALS
Pages411-426
Number of pages16
ISBN (Print)0-8031-2624-7
DOIs
Publication statusPublished - 2000
MoE publication typeA4 Article in a conference publication
EventSymposium on Fatigue Crack Growth Thresholds, Endurance Limits, and Design - Norfolk, United States
Duration: 4 Nov 19985 Nov 1998

Publication series

NameAMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION
PublisherAMERICAN SOCIETY TESTING AND MATERIALS
Volume1372
ISSN (Print)1040-1695

Conference

ConferenceSymposium on Fatigue Crack Growth Thresholds, Endurance Limits, and Design
CountryUnited States
CityNorfolk
Period04/11/199805/11/1998

Keywords

  • fatigue
  • nodular cast iron
  • spheroidal graphite cast iron
  • GRP 500
  • endurance limit
  • nonpropagating cracks
  • fatigue threshold
  • casting defects
  • shrinkage pores
  • NOTCH FATIGUE BEHAVIOR
  • STRENGTH
  • INCLUSIONS
  • OVERLOADS
  • STRESS
  • METALS

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