Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels

Seung Youb Han, Seok S Sohn, Sang Yong Shin, Jin Ho Bae, Hyoung Seop Kim, Sunghak Lee

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

In the present study, effects of microstructure and yield ratio on strain hardening and Bauschinger effect were investigated in two API X80 steel sheets fabricated by controlling the start cooling temperature. The steel whose start cooling temperature was lower had the higher fractions of granular bainite (GB) and martensite-austenite (MA) constituent and the lower fraction of acicular ferrite (AF), and showed the higher yield ratio. According to the results of the strain-reversal test composed of compressive and tensile tests at various compressive pre-strains, the reduction in yield strength of the steel having higher fractions of GB and MA was generally higher than that of the steel having lower fractions. This result could be explained by difference in density of mobile dislocations and by competing mechanisms between Bauschinger effect and strain hardening, which were susceptible to the minute change in pre-strain during the piping process. When the pre-strain was low, e.g., lower than 4%, the steels having low yield ratio and small Bauschinger effect were desirable to minimize the reduction in yield strength.

Original languageEnglish
Pages (from-to)192-199
Number of pages8
JournalMaterials Science and Engineering A
Volume551
DOIs
Publication statusPublished - 2012 Aug 15
Externally publishedYes

Fingerprint

Bauschinger effect
application programming interface
strain hardening
Steel
Application programming interfaces (API)
Strain hardening
steels
microstructure
Microstructure
Bainite
bainite
Martensite
Austenite
Yield stress
yield strength
austenite
martensite
Cooling
Steel sheet
cooling

Keywords

  • API X80 linepipe steel
  • Bauschinger effect
  • Microstructure
  • Strain hardening

ASJC Scopus subject areas

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

Cite this

Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels. / Han, Seung Youb; Sohn, Seok S; Shin, Sang Yong; Bae, Jin Ho; Kim, Hyoung Seop; Lee, Sunghak.

In: Materials Science and Engineering A, Vol. 551, 15.08.2012, p. 192-199.

Research output: Contribution to journalArticle

Han, Seung Youb ; Sohn, Seok S ; Shin, Sang Yong ; Bae, Jin Ho ; Kim, Hyoung Seop ; Lee, Sunghak. / Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels. In: Materials Science and Engineering A. 2012 ; Vol. 551. pp. 192-199.
@article{031fe2ca4d394a3ea7e9a800df066be3,
title = "Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels",
abstract = "In the present study, effects of microstructure and yield ratio on strain hardening and Bauschinger effect were investigated in two API X80 steel sheets fabricated by controlling the start cooling temperature. The steel whose start cooling temperature was lower had the higher fractions of granular bainite (GB) and martensite-austenite (MA) constituent and the lower fraction of acicular ferrite (AF), and showed the higher yield ratio. According to the results of the strain-reversal test composed of compressive and tensile tests at various compressive pre-strains, the reduction in yield strength of the steel having higher fractions of GB and MA was generally higher than that of the steel having lower fractions. This result could be explained by difference in density of mobile dislocations and by competing mechanisms between Bauschinger effect and strain hardening, which were susceptible to the minute change in pre-strain during the piping process. When the pre-strain was low, e.g., lower than 4{\%}, the steels having low yield ratio and small Bauschinger effect were desirable to minimize the reduction in yield strength.",
keywords = "API X80 linepipe steel, Bauschinger effect, Microstructure, Strain hardening",
author = "Han, {Seung Youb} and Sohn, {Seok S} and Shin, {Sang Yong} and Bae, {Jin Ho} and Kim, {Hyoung Seop} and Sunghak Lee",
year = "2012",
month = "8",
day = "15",
doi = "10.1016/j.msea.2012.05.007",
language = "English",
volume = "551",
pages = "192--199",
journal = "Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing",
issn = "0921-5093",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Effects of microstructure and yield ratio on strain hardening and Bauschinger effect in two API X80 linepipe steels

AU - Han, Seung Youb

AU - Sohn, Seok S

AU - Shin, Sang Yong

AU - Bae, Jin Ho

AU - Kim, Hyoung Seop

AU - Lee, Sunghak

PY - 2012/8/15

Y1 - 2012/8/15

N2 - In the present study, effects of microstructure and yield ratio on strain hardening and Bauschinger effect were investigated in two API X80 steel sheets fabricated by controlling the start cooling temperature. The steel whose start cooling temperature was lower had the higher fractions of granular bainite (GB) and martensite-austenite (MA) constituent and the lower fraction of acicular ferrite (AF), and showed the higher yield ratio. According to the results of the strain-reversal test composed of compressive and tensile tests at various compressive pre-strains, the reduction in yield strength of the steel having higher fractions of GB and MA was generally higher than that of the steel having lower fractions. This result could be explained by difference in density of mobile dislocations and by competing mechanisms between Bauschinger effect and strain hardening, which were susceptible to the minute change in pre-strain during the piping process. When the pre-strain was low, e.g., lower than 4%, the steels having low yield ratio and small Bauschinger effect were desirable to minimize the reduction in yield strength.

AB - In the present study, effects of microstructure and yield ratio on strain hardening and Bauschinger effect were investigated in two API X80 steel sheets fabricated by controlling the start cooling temperature. The steel whose start cooling temperature was lower had the higher fractions of granular bainite (GB) and martensite-austenite (MA) constituent and the lower fraction of acicular ferrite (AF), and showed the higher yield ratio. According to the results of the strain-reversal test composed of compressive and tensile tests at various compressive pre-strains, the reduction in yield strength of the steel having higher fractions of GB and MA was generally higher than that of the steel having lower fractions. This result could be explained by difference in density of mobile dislocations and by competing mechanisms between Bauschinger effect and strain hardening, which were susceptible to the minute change in pre-strain during the piping process. When the pre-strain was low, e.g., lower than 4%, the steels having low yield ratio and small Bauschinger effect were desirable to minimize the reduction in yield strength.

KW - API X80 linepipe steel

KW - Bauschinger effect

KW - Microstructure

KW - Strain hardening

UR - http://www.scopus.com/inward/record.url?scp=84862138003&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84862138003&partnerID=8YFLogxK

U2 - 10.1016/j.msea.2012.05.007

DO - 10.1016/j.msea.2012.05.007

M3 - Article

AN - SCOPUS:84862138003

VL - 551

SP - 192

EP - 199

JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

SN - 0921-5093

ER -