Microstructure and mechanical properties of ultrafine grained low carbon steel fabricated by conventional cold-rolling and annealing of martensite (martensite process)

R. Ueji, N. Tsuji, Y. Minamino, Yuichiro Koizumi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A new thermomechanical processing named the martensite process which can easily fabricate the ultrafine grained steels without severe plastic deformation was developed. In this process, martensite is used as the starting structure. The martensite starting structure was conventionally cold-rolled by various reductions and then annealed at various temperatures. The cold-rolled martensite mainly exhibited lamellar structure, which is typical in severely deformed materials. The area fraction of the lamellar structure increased and the mean spacing of the lamellar boundaries decreased with increasing the rolling reduction, accompanying significant strengthening. After subsequent annealing at warm temperatures, the lamellar structure turned to equiaxed ultrafine ferrite grains with carbides precipitated uniformly, and at higher temperatures conventional recrystallization occurred to form coarse grained structure. The recrystallization temperature became lower with increasing the rolling reduction. The specimen rolled to intermediate reduction (50%) performed the largest ductility keeping high strength around 900MPa after warm-temperature annealing.

Original languageEnglish
Title of host publicationUltrafine Grained Materials III
EditorsY.T. Zhu, T.G. Langdon, R.Z. Valiev, S. Lee Semiatin, al et al
Pages143-148
Number of pages6
Publication statusPublished - 2004 Jul 14
EventUltrafine Grained Materials III - Charlotte, NC., United States
Duration: 2004 Mar 142004 Mar 18

Publication series

NameUltrafine Grained Materials III

Other

OtherUltrafine Grained Materials III
CountryUnited States
CityCharlotte, NC.
Period04/3/1404/3/18

Keywords

  • Annealing
  • Cold rolling
  • Martensite
  • Plain low carbon steel
  • Ultrafine grain

ASJC Scopus subject areas

  • Engineering(all)

Fingerprint Dive into the research topics of 'Microstructure and mechanical properties of ultrafine grained low carbon steel fabricated by conventional cold-rolling and annealing of martensite (martensite process)'. Together they form a unique fingerprint.

Cite this