skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Temperature Evolution During Plane Strain Compression Of Tertiary Oxide Scale On Steel

Abstract

An oxide scale layer always forms at the steel surface during hot rolling. This scale layer separates the work roll from the metal substrate. Understanding the deformation behaviour and mechanical properties of the scale is of great interest because it affects the frictional conditions during hot rolling and the heat-transfer behaviour at the strip-roll interface. A thin wustite scale layer (<20 {mu}m) was created under controlled conditions in an original laboratory device adequately positioned in a compression testing machine to investigate plane strain compression. Oxidation tests were performed on an ULC steel grade. After the oxide growth at 1050 deg. C, plane strain compression (PSC) was performed immediately to simulate the hot rolling process. PSC experiments were performed at a deformation temperature of 1050 deg. C, with reduction ratios from 5 to 70%, and strain rates of 10s-1 under controlled gas atmospheres. Results show that for wustite, ductility is obvious at 1050 deg. C. Even after deformation oxide layers exhibit good adhesion to the substrate and homogeneity over the thickness. The tool/sample temperature difference seems to be the reason for the unexpected ductile behaviour of the scale layer.

Authors:
;  [1]; ;  [2]
  1. Department of Metallurgy and Materials Science, Ghent University, Technologiepark 903, B-9052 Gent (Belgium)
  2. Centre for Research in Metallurgy (CRM), Ghent - Liege (Belgium)
Publication Date:
OSTI Identifier:
21056981
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 907; Journal Issue: 1; Conference: 10. ESAFORM conference on material forming, Zaragoza (Spain), 18-20 Apr 2007; Other Information: DOI: 10.1063/1.2729683; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ADHESION; COMPRESSION; DEFORMATION; DUCTILITY; HEAT TRANSFER; INTERFACES; LAYERS; METALS; OXIDATION; OXIDES; REDUCTION; ROLLING; STEELS; STRAIN RATE; STRAINS; SUBSTRATES; SURFACES; TESTING; THERMAL STRESSES

Citation Formats

Suarez, L., Houbaert, Y., Eynde, X. van den, and Lamberigts, M. Temperature Evolution During Plane Strain Compression Of Tertiary Oxide Scale On Steel. United States: N. p., 2007. Web. doi:10.1063/1.2729683.
Suarez, L., Houbaert, Y., Eynde, X. van den, & Lamberigts, M. Temperature Evolution During Plane Strain Compression Of Tertiary Oxide Scale On Steel. United States. doi:10.1063/1.2729683.
Suarez, L., Houbaert, Y., Eynde, X. van den, and Lamberigts, M. Sat . "Temperature Evolution During Plane Strain Compression Of Tertiary Oxide Scale On Steel". United States. doi:10.1063/1.2729683.
@article{osti_21056981,
title = {Temperature Evolution During Plane Strain Compression Of Tertiary Oxide Scale On Steel},
author = {Suarez, L. and Houbaert, Y. and Eynde, X. van den and Lamberigts, M.},
abstractNote = {An oxide scale layer always forms at the steel surface during hot rolling. This scale layer separates the work roll from the metal substrate. Understanding the deformation behaviour and mechanical properties of the scale is of great interest because it affects the frictional conditions during hot rolling and the heat-transfer behaviour at the strip-roll interface. A thin wustite scale layer (<20 {mu}m) was created under controlled conditions in an original laboratory device adequately positioned in a compression testing machine to investigate plane strain compression. Oxidation tests were performed on an ULC steel grade. After the oxide growth at 1050 deg. C, plane strain compression (PSC) was performed immediately to simulate the hot rolling process. PSC experiments were performed at a deformation temperature of 1050 deg. C, with reduction ratios from 5 to 70%, and strain rates of 10s-1 under controlled gas atmospheres. Results show that for wustite, ductility is obvious at 1050 deg. C. Even after deformation oxide layers exhibit good adhesion to the substrate and homogeneity over the thickness. The tool/sample temperature difference seems to be the reason for the unexpected ductile behaviour of the scale layer.},
doi = {10.1063/1.2729683},
journal = {AIP Conference Proceedings},
number = 1,
volume = 907,
place = {United States},
year = {Sat Apr 07 00:00:00 EDT 2007},
month = {Sat Apr 07 00:00:00 EDT 2007}
}
  • Crystallographic texture development and hardening characteristics of a hot-rolled, low-carbon steel sheet due to cold rolling were investigated by idealizing the cold rolling process as plane-strain compression. The starting anisotropy of the test material was characterized by examination of the grain structure by optical microscopy and the preferred crystal orientation distribution by x-ray diffraction. Various heat treatments were used in an effort to remove the initial deformation texture resulting from hot rolling. The plastic anisotropy of the starting material was investigated with tensile tests on samples with the tensile axis parallel, 45{degree}, and perpendicular to the rolling direction. The grainmore » structure after plane-strain compression was studied by optical microscopy, and the new deformation texture was characterized by x-ray diffraction pole figures. These figures are compared with the theoretical pole figures produced from a Taylor-like polycrystal model based on a pencil-glide slip system. The uniaxial tensile stress-strain curve and the plane-strain, compressive stress-strain curve of the sheet were used to calibrate the material parameters in the model. The experimental pole figures were consistent with the findings in the theoretical study. The experimental and theoretical results suggest that the initial texture due to hot rolling was insignificant as compared with the texture induced by large strains under plane-strain compression.« less
  • Constant true strain rate simple compression tests were conducted on annealed, polycrystalline samples of {alpha}-brass and MP35N, and the evolution of the true stress ({sigma})-true strain ({var_epsilon}) response was documented. From these data, the strain hardening rate was numerically computed, normalized with shear modulus (G), and plotted against both ({sigma} {minus} {sigma}{sub 0})/G ({sigma}{sub 0} being the initial yield strength of the alloy) and {var_epsilon}. Such four distinct stages of strain hardening: stage A, with a steadily decreasing strain hardening rate up to a true strain of about {minus}0.08; stage B, with an almost constant strain hardening rate up tomore » a true strain of about {minus}0.2; stage C, with a steadily decreasing strain hardening rate up to a true strain of about {minus}0.55; and a final stage D, again with an almost constant strain hardening rate. Optical microscopy and transmission electron microscopy (TEM) were performed on deformed samples. Based on these experimental observations, the authors have developed and presented a physical description of the microstructural phenomena responsible for the various strain hardening stages observed in low SFE fcc alloys.« less
  • Plane strain forming in commercial processes commonly includes elevated temperature multi-step reductions. An understanding of microstructural development during this process is critical because it dictates the properties of the material subsequent to hot forming. Earing behavior, formability, and mechanical response of the final product are all dependent upon the processing parameters which dictate microstructural evolution. The present work focuses upon the development of hot deformation textures in aluminum during this type of processing. Commercial purity aluminum specimens exhibiting two different starting textures were deformed in channel die compression experiments to simulate the plane strain deformation conditions imposed by the rollingmore » mill. Initial structures consisted of a randomly textured material and a preferentially cube orientated texture to investigate the effects of starting texture on hot deformation processing and the resulting microstructures. Rate and temperature dependence of texture evolution was experimentally and theoretically investigated in conjunction with this. The relative stability of cube orientations within polycrystals deformed in plane strain is demonstrated for certain deformation conditions. Finally, experimental observations of the evolution of orientation flow from the alpha to the beta fiber are discussed.« less
  • Strain softening behavior has been found at meso scale using micro-compression testing in an ultrafine-grained (UFG) pure copper by comparison with the typical strain hardening in conventional coarse-grained (CG) material. Microstructural observations show that grain size remains nearly the same including the fraction of high-angle grain boundaries during micro-compression in UFG pure copper. The Kernel average misorientation(KAM) distribution measured by electron backscatter diffraction (EBSD), as a statistical method, is applied to qualitatively evaluate dislocation density in the interior of the grains. It is suggested that the deformation mechanisms are dominated by grain boundary sliding and grain rotation accompanied by dislocationmore » slip in UFG pure copper, which demonstrates that the strain softening behavior is primarily caused by dislocation annihilation during micro-compression.« less
  • The (hcp) {var_epsilon}-martensite formation and the elastic strain evolution of individual (fcc) austenite grains in metastable austenitic stainless steel AISI 301 has been investigated during in situ tensile loading up to 5% applied strain. The experiment was conducted using high-energy X-rays and the 3DXRD technique, enabling studies of individual grains embedded in the bulk of the steel. Out of the 47 probed austenite grains, one could be coupled with the formation of {var_epsilon}-martensite, using the reported orientation relationship between the two phases. The formation of ?-martensite occurred in the austenite grain with the highest Schmid factor for the active {l_brace}111{r_brace}<12{barmore » 1}> slip system.« less