Deformation structure and subsurface fatigue crack generation in austenitic steels at low temperature

• UMEZAWA O.

抄録

In order to progress in the understanding of fatigue crack generation for high-strength alloys, the subsurface fatigue crack initiation sites were characterized and the deformation structure was investigated for the solution-treated 24Cr-15Ni-4Mn-0.3N and 32Mn-7Cr-0.1N austenitic steels. High-cycle fatigue tests of those steels were carried out at 4,77, and 293 K. Subsurface crack initiation was detected in the lower-peak stress and/or in the longer-life range at the three temperatures. The subsurface crack initiation sites were intergranularly formed. The localized deformation and/or strain concentration by dislocation arrays of the (111)-<110> system assisted intergranular cracking due to incompatibility at grain boundaries. Dislocation movements were restricted to their slip planes. Even at the lower stress level, dislocations had generated in more than one slip system and piled up to a grain boundary. The peak cyclic stress was lowered with the increasing size of the subsurface crack initiation site. The dependence of the subsurface crack size on the peak cyclic stress was discussed.

収録刊行物

• Metallurgical and materials transactions. A, Physical metallurgy and materials science

  Metallurgical and materials transactions. A, Physical metallurgy and materials science 29 (3), 809-822, 1998-03

  ASM International

詳細情報

• CRID: 1570291226780993152
• NII論文ID: 80010214768
• NII書誌ID: AA10987657
• ISSN: 10735623
• Web Site: http://hdl.handle.net/10131/7902
• 本文言語コード: en
• データソース種別:
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