Inverse temperature dependence of toughness in an ultrafine grain-structure steel

Yuuji Kimura, Tadanobu Inoue, Fuxing Yin, Kaneaki Tsuzaki

Research output: Contribution to journalArticle

225 Citations (Scopus)

Abstract

Materials are typically ductile at higher temperatures and become brittle at lower temperatures. In contrast to the typical ductile-to-brittle transition behavior of body-centered cubic (bcc) steels, we observed an inverse temperature dependence of toughness in an ultrahigh-strength bcc steel with an ultrafine elongated ferrite grain structure that was processed by a thermomechanical treatment without the addition of a large amount of an alloying element. The enhanced toughness is attributed to a delamination that was a result of crack branching on the aligned {100} cleavage planes in the bundles of the ultrafine elongated ferrite grains strengthened by nanometer-sized carbides. In the temperature range from 60° to -60°C, the yield strength was greater, leading to the enhancement of the toughness.

Original languageEnglish
Pages (from-to)1057-1060
Number of pages4
JournalScience
Volume320
Issue number5879
DOIs
Publication statusPublished - May 23 2008
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General

Fingerprint Dive into the research topics of 'Inverse temperature dependence of toughness in an ultrafine grain-structure steel'. Together they form a unique fingerprint.

  • Cite this