FRACTURE EVALUATION OF ENERGY COMPONENTS WITH LOCAL BRITTLE ZONES
Abstract
The fracture toughness in the testing of multi-pass welds and heat-affected zones is remarkably sensitive to the microstructures in the vicinity of the crack tip of test specimen. Therefore, the introduction of the pre-crack to the weld and heat-affected zone specimen should be done most carefully. However, since there is an uncertainty of the crack tip position in fatigue precracking, it becomes common to section near the fatigue pre-crack front after testing is complete, and to examine the cross section in order to identify the position in weld and heataffected zone microstructures, the so-called local brittle zones. Concerning this sectioning technique, the precise experimental procedure is specified in this article.
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References
BS 5762, Methods for crack opening displacement (COD) testing, The British Standards Institution, London 1979.
Praunseis, Z., Toyoda, M., Sundararajan, T.: Fracture behaviours of fracture toughness testing specimens with metallurgical heterogeneity along crack front. Steel res., Sep. 2000, 71, no 9,
Praunseis, Z., Sundararajan, T., Toyoda, M., Ohata, M.: The influence of soft root on fracture behaviors of high-strength, low-alloyed (HSLA) steel weldments. Mater. manuf. process., 2001, vol. 16, 2
Toyoda, M.: Fracture toughness evaluation of steel welds, Book of Mechanics, Osaka University, 1989.
Praunseis, Z.: The influence of Strength Under-matched Weld Metal containing Heterogeneous Regions on Fracture Properties of HSLA Steel Weld Joint (Dissertation in English). Faculty of Mechanical Engineering, University of Maribor, Slovenia, 1998
ASTM E 1152-87, Standard test method for determining J-R curves, Annual Book of ASTM Standards, Vol. 03.01, American Society for Testing and Materials, Philadelphia, 1990.
ASTM E 1290-91, Standard test method for crack-tip opening displacement (CTOD) fracture toughness measurement, American Society for Testing and Materials, Philadelphia, 1991.
