Microstructure near scratch on alloy 690TT and stress corrosion induced by scratching

Fanjiang Meng, Jianqiu Wang, En Hou Han, Tetsuo Shoji, Wei Ke

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

The microstructure and stress corrosion cracking (SCC) behavior of scratched zone on alloy 690TT were studied by using microhardness, TEM, EBSD-OIM and immersion experiment in caustic solution. It was found that a deformed hardening layer with a dimension range of 100 μm was produced near the scratch. TEM and EBSD-OIM observations showed that the grains at shallow surface of scratch groove were refined to nano-size. SCC tests for scratched alloy 690TT were performed in caustic solution at high temperature with or without addition of lead oxides. The results showed that SCC cracks initiated and propagated at scratch banks and scratch grooves. Grain boundaries, twin boundaries deformed and microcracks produced during scratching process are preferential sites for SCC. The oxide films formed on scratch groove were loosed by lead. The SCC crack length increased with increase of lead content. Scratched alloy 690TT is susceptible to SCC.

Original languageEnglish
Pages (from-to)839-846
Number of pages8
JournalJinshu Xuebao/Acta Metallurgica Sinica
Volume47
Issue number7
DOIs
Publication statusPublished - 2011 Jul 1

Keywords

  • Microstructure
  • Ni base alloy 690
  • Stress corrosion cracking
  • Surface scratch

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys

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