Distribution of Grain-Boundary Length and Inclination of Type 304 Stainless Steel and Its Effects on Small Crack Initiation and Growth under Creep-Fatigue Conditions

Takayuki Kitamura, Naoya Tada, Yoshihide Kuriyama, Ryuichi Ohtani

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2 Citations (Scopus)

Abstract

In order to elucidate the microstructural effect on initiation and growth of intergranular small cracks under creep-fatigue conditions, we discuss the randomness of grain-boundary length and inclination. This study consists of the following investigations; (1)the length and inclination of grain boundaries of a stainless steel, SUS 304, are measured by means of image analysing system; (2) a numerical generation method of polycrystal grains is developed on the basis of an isotropic grain growth model; and (3) the crack length and inclination are measured by means of an image analysing system under creep-fatigue conditions. The results obtained from each investigation are summarized as follows, respectively. (A) The grain-boundary inclination of the steel is uniformly distributed and the length between adjacent triple points has a wide scatter between 10 and 100 μm. The length and the inclination are independent of each other (B) The simulated length and inclination of grain-boundaries coincides well with the actual grains of the steel. This method is useful for the stochastic simulation of initiation and growth of microstructurally small cracks, which will be reported in the next paper. (C) Cracks preferentially initiate on the grain boundaries perpendicular to the stress axis by a span between adjacent triple points. The crack growth rate shows a little dependence on the crack tip angle.

Original languageEnglish
Pages (from-to)702-707
Number of pages6
JournalTransactions of the Japan Society of Mechanical Engineers Series A
Volume56
Issue number524
DOIs
Publication statusPublished - Jan 1 1990
Externally publishedYes

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Keywords

  • Crack Growth
  • Crack Initiation
  • Fatigue at Elevated Temperature
  • Grain-Boundary Inclination
  • Grain-Boundary Length
  • Image Analyses. Small Crack
  • Numerical Analysis
  • Statistical Treatment
  • Type 304 Stainless Steel

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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