Crystal plasticity simulation on effect of heterogeneous-nanostructure induced by severe cold-rolling on mechanical properties of austenitic stainless steel

Yoshiteru Aoyagi, Chihiro Watanabe, Masakazu Kobayashi, Yoshikazu Todaka, Hiromi Miura

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Synopsis: Severe plastic deformation has attracted interests as one of the breakthrough procedures to improve various properties of metals and alloys. Recently, it has been revealed that heavy cold rolling of some kinds of austenitic stainless steels can cause ultrafine-grained structure comparable with those achieved by severe plastic deformation. Coarse initial grains were fragmented by deformation induced microstructure to develop heterogeneous nanostructure. Tensile strength of heterogeneous-nanostructured stainless steel exceeds 2 GPa. It is considered that high strength of heterogeneous-nanostructured metals is attributed to such peculiar microstructure with dispersed "eye-shaped twin domains". In this study, microstructural mechanisms and factors which contribute to macroscopic strength of heterogeneous-nanostructured austenitic stainless steel were evaluated on the basis of multiscale crystal plasticity simulation. Microstructure of heavily cold-rolled SUS316LN austenitic stainless steel was investigated by transmission electron microscopy, and stress-strain curves were attained by tensile tests. It was observed that microstructure of SUS316LN manufactured by 92% cold rolling was composed of deformation nano-twins, shear bands, and lamella structure. Evaluation of mechanical properties of heterogeneous-nanostructured SUS316LN was conducted using crystal plasticity finite element simulation considering microstructural information, such as dislocation density, crystal orientation, shape of grains, and dislocation sources. Information of microstructure obtained by electron backscatter diffraction, e.g. geometry of heterogeneous nanostructures and crystal orientation, were introduced to computational models for multiscale crystal plasticity simulation. It was revealed that deformation behavior depends on the tensile direction and the strength increases with the increase of volume fraction of twin domains as well as nano-twin and lamellar inter-spacings.

Original languageEnglish
Pages (from-to)140-149
Number of pages10
JournalTetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
Volume105
Issue number2
DOIs
Publication statusPublished - 2019 Feb

Keywords

  • Austenitic stainless
  • Crystal plasticity
  • Dislocation
  • Heterogeneous-nanostructured metals
  • Nano-twin
  • Simulation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Crystal plasticity simulation on effect of heterogeneous-nanostructure induced by severe cold-rolling on mechanical properties of austenitic stainless steel'. Together they form a unique fingerprint.

Cite this