Paper Title:
Microstructure Evolution during Warm Deformation of Low Carbon Steel with Dispersed Cementite
  Abstract

The microstructure evolution and mechanical behavior during large strain of a 0.16%CMn steel has been investigated by warm torsion tests. These experiments were carried out at 685 °C at equivalent strain rate of 0.1 s-1. The initial microstructure composed of a martensite matrix with uniformly dispersed fine cementite particles was attained by quenching and tempering. The microstructure evolution during tempering and straining was performed through interrupted tests. As the material was reheated to testing temperature, well-defined cell structure was created and subgrains within lath martensite were observed by TEM; strong recovery took place, decreasing the dislocation density. After 1 hour at the test temperature and without straining, EBSD technique showed the formation of new grains. The flow stress curves measured had a peculiar shape: rapid work hardening to a hump, followed by an extensive flow-softening region. 65% of the boundaries observed in the sample strained to ε = 1.0 were high angle grain boundaries. After straining to ε = 5.0, average ferrite grain size close to 1.5 1m was found, suggesting that dynamic recrystallization took place. Also, two sets of cementite particles were observed: large particles aligned with straining direction and smaller particles more uniformly dispersed. The fragmentation or grain subdivision that occurred during reheating and tempering time was essential for the formation of ultrafine grained microstructure.

  Info
Periodical
Materials Science Forum (Volumes 558-559)
Edited by
S.-J.L. Kang, M.Y. Huh, N.M. Hwang, H. Homma, K. Ushioda and Y. Ikuhara
Pages
505-510
DOI
10.4028/www.scientific.net/MSF.558-559.505
Citation
J. Gallego, A. M. Jorge, O. Balancin, "Microstructure Evolution during Warm Deformation of Low Carbon Steel with Dispersed Cementite", Materials Science Forum, Vols. 558-559, pp. 505-510, 2007
Online since
October 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Julia Ivanisenko, Ian MacLaren, Xavier Sauvage, Ruslan Valiev, Hans Jorg Fecht
Abstract:The paper presents an overview of a number of unusual phase transformations which take place in pearlitic steels in conditions of the severe...
133
Authors: S.V.S. Narayana Murty, Shiro Torizuka
Abstract:Ultrafine-grained steels with a grain size of about one micron offer the prospect of high strength coupled with high toughness among...
211
Authors: S. Torizuka, Eijiro Muramatsu
Abstract:Ultrafine grain refinement to 1 m deteriorates the uniform elongation in the tensile tests of steels. Such loss of ductility has been argued...
3543
Authors: Long Fei Li, Wei Chen, Wang Yue Yang, Zu Qing Sun
Abstract:Microstructure evolution and mechanical properties of hypereutectoid steel with the microduplex (α+θ) structures formed by hot deformation of...
246
Authors: Matteo Caruso, Hector Verboomen, Stéphane Godet
Chapter 16: Steels
Abstract:The aim of this research is to investigate the effect of Cr and Al (strong ferrite formers) on the strain-induced γ-to-pearlite...
666