Effects of fine particle peening on fatigue strength of a TRIP-aided martensitic steel

Koh ichi Sugimoto, Yuta Mizuno, Masahiro Natori, Tomohiko Hojo

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

The effects of fine particle peening on the fatigue properties of a transformation-induced plasticity-aided martensitic steel with a chemical composition of 0.2% C, 1.5% Si, 1.5% Mn, 1.0% Cr, and 0.05% Nb (mass%) were investigated for applications in precision gears. When this steel was subjected to fine particle peening after heat treatment, higher fatigue limits and lower notch sensitivity were achieved compared with those of SNCM420 martensitic steel. The increased fatigue limits are principally associated with higher hardness and compressive residual stress on and just below the surface, as well as low surface roughness. Fine particle peening also increased the threshold stress intensity factor range in stage I, and decreased the crack propagation rate in stage II in this steel. The crack propagation behavior was mainly suppressed by (1) high hardness and high compressive residual stress, and (2) the strain-induced martensite transformation of retained austenite and high internal stress resulting from a difference in flow stress between the soft martensite matrix and the finely dispersed hard MA-like phase that developed during fatigue deformation.

Original languageEnglish
Pages (from-to)206-214
Number of pages9
JournalInternational Journal of Fatigue
Volume100
DOIs
Publication statusPublished - 2017 Jul 1

Keywords

  • Fatigue strength
  • Fine particle peening
  • Residual stress
  • Retained austenite
  • TRIP steel

ASJC Scopus subject areas

  • Modelling and Simulation
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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