Microstructural analysis of cracking phenomenon occurring during cold rolling of (0.1~0.7)C-3Mn-5Al lightweight steels

Seok S Sohn, Byeong Joo Lee, Sunghak Lee, Jai Hyun Kwak

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

An investigation was conducted into the cracking phenomenon occurring during the cold rolling of lightweight steel plates. Four steels of varying C contents were fabricated and steel plates containing C contents of 0.5wt% or higher were cracked during the initial stage of the cold rolling. The steels were basically composed of ferrite grains and -carbides in a band shape, but the volume fraction and thickness of κ-carbide band increased as the C content increased. Microstructural observation of the deformed region of fractured tensile specimens revealed that deformation bands were homogeneously formed in wide areas of ferrite matrix in the steels containing C contents of 0.3 wt% or lower, while κ-carbide bands were hardly deformed or cracked. In the steels containing high C contents of 0.5 wt% or higher, on the other hand, microcracks were initiated mostly at fine proeutectoid ferrite located within κ-carbide bands, and were grown further to coalesce with other microcracks to form long cracks. To prevent the cracking, thus, the proeutectoid ferrite should be minimized by the hot rolling in the (α+γ) two phase region. As practical methods, the content of C below 0.5% or Al above 5% was suggested to expand the (α+γ) phase region.

Original languageEnglish
Pages (from-to)43-53
Number of pages11
JournalMetals and Materials International
Volume21
Issue number1
DOIs
Publication statusPublished - 2015 Jan 1
Externally publishedYes

Fingerprint

cold rolling
Steel
Cold rolling
steels
carbides
Ferrite
Carbides
ferrites
microcracks
Microcracks
Hot rolling
Volume fraction
cracks
Cracks
matrices

Keywords

  • ferritic lightweight steel
  • fracture
  • phase diagram
  • rolling
  • scanning electron microscopy

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

Cite this

Microstructural analysis of cracking phenomenon occurring during cold rolling of (0.1~0.7)C-3Mn-5Al lightweight steels. / Sohn, Seok S; Lee, Byeong Joo; Lee, Sunghak; Kwak, Jai Hyun.

In: Metals and Materials International, Vol. 21, No. 1, 01.01.2015, p. 43-53.

Research output: Contribution to journalArticle

@article{92723ba34ed14df4bc75e8077da952d8,
title = "Microstructural analysis of cracking phenomenon occurring during cold rolling of (0.1~0.7)C-3Mn-5Al lightweight steels",
abstract = "An investigation was conducted into the cracking phenomenon occurring during the cold rolling of lightweight steel plates. Four steels of varying C contents were fabricated and steel plates containing C contents of 0.5wt{\%} or higher were cracked during the initial stage of the cold rolling. The steels were basically composed of ferrite grains and -carbides in a band shape, but the volume fraction and thickness of κ-carbide band increased as the C content increased. Microstructural observation of the deformed region of fractured tensile specimens revealed that deformation bands were homogeneously formed in wide areas of ferrite matrix in the steels containing C contents of 0.3 wt{\%} or lower, while κ-carbide bands were hardly deformed or cracked. In the steels containing high C contents of 0.5 wt{\%} or higher, on the other hand, microcracks were initiated mostly at fine proeutectoid ferrite located within κ-carbide bands, and were grown further to coalesce with other microcracks to form long cracks. To prevent the cracking, thus, the proeutectoid ferrite should be minimized by the hot rolling in the (α+γ) two phase region. As practical methods, the content of C below 0.5{\%} or Al above 5{\%} was suggested to expand the (α+γ) phase region.",
keywords = "ferritic lightweight steel, fracture, phase diagram, rolling, scanning electron microscopy",
author = "Sohn, {Seok S} and Lee, {Byeong Joo} and Sunghak Lee and Kwak, {Jai Hyun}",
year = "2015",
month = "1",
day = "1",
doi = "10.1007/s12540-015-1006-8",
language = "English",
volume = "21",
pages = "43--53",
journal = "Metals and Materials International",
issn = "1598-9623",
publisher = "Korean Institute of Metals and Materials",
number = "1",

}

TY - JOUR

T1 - Microstructural analysis of cracking phenomenon occurring during cold rolling of (0.1~0.7)C-3Mn-5Al lightweight steels

AU - Sohn, Seok S

AU - Lee, Byeong Joo

AU - Lee, Sunghak

AU - Kwak, Jai Hyun

PY - 2015/1/1

Y1 - 2015/1/1

N2 - An investigation was conducted into the cracking phenomenon occurring during the cold rolling of lightweight steel plates. Four steels of varying C contents were fabricated and steel plates containing C contents of 0.5wt% or higher were cracked during the initial stage of the cold rolling. The steels were basically composed of ferrite grains and -carbides in a band shape, but the volume fraction and thickness of κ-carbide band increased as the C content increased. Microstructural observation of the deformed region of fractured tensile specimens revealed that deformation bands were homogeneously formed in wide areas of ferrite matrix in the steels containing C contents of 0.3 wt% or lower, while κ-carbide bands were hardly deformed or cracked. In the steels containing high C contents of 0.5 wt% or higher, on the other hand, microcracks were initiated mostly at fine proeutectoid ferrite located within κ-carbide bands, and were grown further to coalesce with other microcracks to form long cracks. To prevent the cracking, thus, the proeutectoid ferrite should be minimized by the hot rolling in the (α+γ) two phase region. As practical methods, the content of C below 0.5% or Al above 5% was suggested to expand the (α+γ) phase region.

AB - An investigation was conducted into the cracking phenomenon occurring during the cold rolling of lightweight steel plates. Four steels of varying C contents were fabricated and steel plates containing C contents of 0.5wt% or higher were cracked during the initial stage of the cold rolling. The steels were basically composed of ferrite grains and -carbides in a band shape, but the volume fraction and thickness of κ-carbide band increased as the C content increased. Microstructural observation of the deformed region of fractured tensile specimens revealed that deformation bands were homogeneously formed in wide areas of ferrite matrix in the steels containing C contents of 0.3 wt% or lower, while κ-carbide bands were hardly deformed or cracked. In the steels containing high C contents of 0.5 wt% or higher, on the other hand, microcracks were initiated mostly at fine proeutectoid ferrite located within κ-carbide bands, and were grown further to coalesce with other microcracks to form long cracks. To prevent the cracking, thus, the proeutectoid ferrite should be minimized by the hot rolling in the (α+γ) two phase region. As practical methods, the content of C below 0.5% or Al above 5% was suggested to expand the (α+γ) phase region.

KW - ferritic lightweight steel

KW - fracture

KW - phase diagram

KW - rolling

KW - scanning electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=84921822308&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84921822308&partnerID=8YFLogxK

U2 - 10.1007/s12540-015-1006-8

DO - 10.1007/s12540-015-1006-8

M3 - Article

VL - 21

SP - 43

EP - 53

JO - Metals and Materials International

JF - Metals and Materials International

SN - 1598-9623

IS - 1

ER -