Paper Title:
Ductility of Microalloyed Steels during Hot Deformation
  Abstract

The ductility behaviour experienced by steels for linepipe (LP) applications in a temperature range generally from 700°C to 1200°C is a widely studied subject in steel research, especially for its implication on cracking during continuous casting and rolling. Hot tensile / torsion tests on as-cast products, conducted until fracture, are normally used to characterise the hot deformability behaviour. Depending on the industrial hot deformation process within which the steel aptitude is being investigated, other types of tests can be more adequate. With the aim to characterize the hot deformability behaviour in terms of the damages each steel presents at moderate strain levels (i.e. far from the onset of necking), a special device for interrupted hot tensile tests, followed by immediate quenching (i.e. to “freeze” the microstructure) was developed. Various industrial steels with different starting microstructures (ad hoc in-lab heat treatments performed before testing) were tested by this method, and subsequent metallurgical investigations of the strained samples were carried out to identify, for each case, the damage mechanism and the microstructure features having the major influence on ductility loss. As a result, it was found that (i) microstructural damages at moderate strain levels can be much better described throughout interrupted hot tensile tests, (ii) different compositions and starting microstructures within the industrial LP scenario lead always to microstructural damages at relatively high deformation temperatures (e.g. 950°C) and moderate strains (e.g. 0.1 to 0.2, very far from the onset of necking), (iii) the common mechanism by which LP steels start voiding is the grain boundary sliding and (iv) the intergranular voids, once formed, grow longer in coarser microstructures.

  Info
Periodical
Materials Science Forum (Volumes 638-642)
Main Theme
Edited by
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
Pages
3362-3367
DOI
10.4028/www.scientific.net/MSF.638-642.3362
Citation
A. Mannucci, E. Anelli, M. Armengol, M. Vedani, "Ductility of Microalloyed Steels during Hot Deformation", Materials Science Forum, Vols. 638-642, pp. 3362-3367, 2010
Online since
January 2010
Export
Price
$35.00
Share

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

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

Authors: Edgar García S., E. Treviño L., Armando Salinas-Rodríguez
Abstract:The hot tensile ductility of solution treated Si-Al electrical steels was investigated at temperatures between 850 and 1150 °C. Samples for...
103
Authors: H.J. McQueen
Abstract:Inherent failure mechanisms at elevated temperature are primarily wedge crack growth at triple junctions arising from differential grain...
285
Authors: Ke Han
Abstract:This paper reviews research on nanostructured high strength wires and strips. Such materials have sufficient ductility and they have found...
383
Authors: Fang Dong, Cheng Su, Yuan Yuan Bai
Abstract:Hot-ductility tests of the microalloyed Q345B structural steel were performed in a tensile machine of Gleeble-1500D at different strain rates...
150
Authors: Fang Dong, Cheng Su
Chapter 2: Iron and Steel
Abstract:The V、Ti、Nb micro-alloyed Q345B structural steel was made the hot tensile test by Gleeble-1500D thermal simulation testing machine. It...
223