Correlation Between Fracture Mechanics Parameters and Fracture Characteristics in Austenites

Authors

A. Seibold, Kraftwerk Union AG
R. Löhberg, Kraftwerk Union AG

Abstract

Fracture surfaces of austenitic samples tested at room temperature show a correlation between fracture characteristics, Δ K-value and R-ratio: 1) at low Δ K-values up to 400 N/mm³/² and stress ratios of R = 0.1 and R = 0.7, no fatigue striations but fan-like features and flat facets can be seen; 2) fatigue striations, but no facets exist at Δ K-values greater than 900 N/mm³/² and R = 0.1; 3) at a higher stress ratio of R = 0.7 the facets disappear already at lower Δ K-values of about 650 N/mm³/².

Applied to failure analysis, this correlation permits an estimate of operating level of fatigue stress as a result of the evaluation of fatigue fracture characteristics.

Fracture characteristics of samples tested at 200°C differ from those tested at room temperature, but do not show any appreciable changes in fracture features dependent on the Δ K-value and R-ratio.

Recommended Citation

Seibold, A. and Löhberg, R. (1985) "Correlation Between Fracture Mechanics Parameters and Fracture Characteristics in Austenites," Scanning Electron Microscopy: Vol. 1985: No. 3, Article 14.
Available at: https://digitalcommons.usu.edu/electron/vol1985/iss3/14