| Abstract |
| A study has been made to investigate the effect of the substitution of tungsten(W) for molybdenum(Mo) on the microstructure and the fatigue crack growth (FCG) behavior of duplex stainless steels. For the homogenized specimens, microstructures and the FCG properties were not largely changed with the Increase in W content. However, when the alloys were aged at 900℃ for 30 minutes after homogenization, the apparent FCG resistance was significantly increased as compared to that of homogenized specimens. It was mainly attributed to the precipitation of the e and x phases in the aged microstructures, which induced higher levels of crack closure than the homogenized microstructures during the crack propagation. With an increase in W content, the quantity and size of the brittle precipitates decreases and the ductility of the aged alloys Increases. Accordingly, the intrinsic FCG resistance of the aged alloys is Improved with increasing W contents. |
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| Key Words |
| Fatigue crack growth, Duplex stainless steel, phase, Crack closure |
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