YAO Kefu TANG Naiyong CHEN Nanping Tsinghua University
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Beijing
,
China [Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A213—A218
,
Ph.D.Student
,
Dept.of Materials Sci.and Eng.
,
Tsinghua University
,
Beijing
,
China
金属学报(英文版)
The development of dislocation structures in the plastic zone ahead of a crack tip has been in- vestigated in a duplex stainless steel during in-situ deformation experiments in a scanning transmission electron microscope.It was found that the dislocation distribution was significantly different in the ferrite and in the austenite.In the ferrite grains,the dislocations emitted by the crack tip may cross-slip out of the original slip planes and form a broad plastic zone.However,in the austenite,the dislocation free zone is small and the dislocations emitted by the crack pile up in its slip plane.The selection of slip systems at the crack tip depends on the crack tip Schmid factors in both phases.But after large deformation,the selection of the second slip systems at the craek tip in austenite does not depend on the Schmid factors.
关键词:
crack tip
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