Fatigue crack initiation and propagation in butt joint welds of an ultrahigh-strength steel
- Northwestern Polytechnical Univ., Xian (China)
In this paper, the fatigue crack initiation (FCI) from notches and fatigue crack propagation (FCP) in different zones of welds in butt joints of 30CrMnSiNi2A steel were investigated. General formulas for the FCI life and the FCP rate of the welds are examined, and an approach to predicting the FCI life is offered. The research indicates that the postweld isothermal quenching treatment improves both the microstructure and fatigue resistance of the welds. Little difference is found in the FCI resistance of the base metal, weld metal and weld interface, although the microstructural effect on the FCP rate is observed. In the near-threshold region, the FCP rates of the weld interface are higher than those of the base metal but lower than those of the weld metal. The discontinuities on the notch surface have a detrimental influence on the FCI resistance of the welds investigated. The results further indicate that, in order to predict the fatigue life of the welded structures accurately, the test results of FCI life and FCP rate should be properly selected according to the FCI location and FCP path in the structures.
- OSTI ID:
- 6543994
- Journal Information:
- Welding Journal (Miami); (United States), Journal Name: Welding Journal (Miami); (United States) Vol. 72:2; ISSN 0043-2296; ISSN WEJUA3
- Country of Publication:
- United States
- Language:
- English
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