Characterization of age hardening mechanism of low-temperature aged low-carbon steel by transmission electron microscopy

Yasuhito Kawahara, Takuya Maeda, Keisuke Kinoshita, Jun Takahashi, Hideaki Sawada, Ryo Teranishi, Kenji Kaneko

Research output: Contribution to journalArticlepeer-review

Abstract

Low-temperature aging treatment at 323 K results in the dramatical increase in hardness in low-carbon ferritic steels quenched from 983 K, possibly caused by carbon clusters and/or fine ε-carbides. In this study, transmission electron microscopy (TEM) analysis was carried out to characterize the change of the microstructure during the low-temperature aging treatment. Until the early stage of the peak hardness, the carbon clusters were formed homogeneously with zig-zag structures. At the latter stage of the peak hardness, it was found that the ε-carbides were partially precipitated within the carbon clusters, which suggested that the carbon clusters might have acted as the precursors of ε-carbides. In-situ tensile TEM observations showed that dislocation motions were free-glide type, and carbon clusters and fine-carbides interacted with dislocations via cutting-type. Dislocation interaction force was also evaluated, which suggested that the lattice misfit played as important role of the interaction mechanism.

Original languageEnglish
Article number111579
JournalMaterials Characterization
Volume183
DOIs
Publication statusPublished - Jan 2022

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Characterization of age hardening mechanism of low-temperature aged low-carbon steel by transmission electron microscopy'. Together they form a unique fingerprint.

Cite this