The Influence of Microstructural Morphology and Prestrain on Fatigue Crack Propagation of Dual-phase Steels in the Near-threshold Region.

• Nakajima Katsumi

  Department of Materials Science and Engineering, Nagoya University

• Kamiishi Susumu

  Graduate Student, Nagoya University

• Yokoe Masahiro

  Graduate Student, Nagoya University

• Miyata Takashi

  Department of Materials Science and Engineering, Nagoya University

Abstract

The influence of microstructure and prestrain on fatigue crack propagation in the near threshold region was studied for dual-phase steels with different microstructural morphologies. The material with martensite phases dispersed in ferrite matrix exhibited a higher nominal stress intensity range and a lower crack propagation rate than those of material with a continuous martensite phase around ferrite grains. Prestrain prior to fatigue testing resulted in a decrease of nominal stress intensity range in both materials. However there was a slight difference among all the materials in the effective stress intensity range. The microstructural morphology and prestrain exerted a great influence on crack path and that caused a large difference in crack closure. A quantitative correlation existed between crack closure level and surface roughness of fatigue fracture.

Journal

• ISIJ International

  ISIJ International 39 (5), 486-492, 1999

  The Iron and Steel Institute of Japan

Keywords

• fatigue
• large crack
• crack propagation
• crack closure
• heat treatment
• microstructural morphology
• prestrain
• fractography
• laser microscopy
• dual phase steel

Details

• CRID: 1390282681428743424
• NII Article ID: 10002463243
• NII Book ID: AA10680712
• DOI: 10.2355/isijinternational.39.486
• ISSN: 13475460
• ISSN: 09151559
• Web Site: http://www.jstage.jst.go.jp/article/isijinternational1989/39/5/39_5_486/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed