Finite Element Modelling Of Tensile Test For Micro-Alloyed Low Carbon Steel At High Temperature

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Finite Element Modelling Of Tensile Test For

Micro-Alloyed Low Carbon Steel At High Temperature

Changli Zhang, Michel Bellet, Manuel Bobadilla, Houfa Shen, Baicheng Liu

To cite this version:

Changli Zhang, Michel Bellet, Manuel Bobadilla, Houfa Shen, Baicheng Liu. Finite Element Modelling Of Tensile Test For Micro-Alloyed Low Carbon Steel At High Temperature. Acta Metallurgica Sinica, Springer Verlag, 2010, 46 (10), pp.Pages 1206-1214. �10.3724/SP.J.1037.2010.01206�. �hal-00570495�

2010^$10^{H x}1206—1214 ACTA METALLURGICA SINICA Oct. 2010 pp.1206–1214

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1) Michel Bellet²⁾ Manuel Bobadilla³⁾

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2) Mines–ParisTech, Centre de Mise en Forme des Mat´eriaux (CEMEF), Sophia Antipolis, France 06904 3) ArcelorMittal, Research and Development, Maizi`eres–l`es–Metz, France 57283

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FINITE ELEMENT MODELLING OF TENSILE TEST FOR MICRO–ALLOYED LOW CARBON STEEL AT

HIGH TEMPERATURE

ZHANG Changli¹⁾, Michel Bellet²⁾, Manuel Bobadilla³⁾, SHEN Houfa¹⁾, LIU Baicheng¹⁾

1) Key Laboratory for Advanced Materials Processing Technology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084

2) Mines–ParisTech, Centre de Mise en Forme des Mat´eriaux (CEMEF), Sophia Antipolis, France 06904 3) ArcelorMittal, Research and Development, Maizi`eres–l`es–Metz, France 57823

Correspondent: SHEN Houfa, associate professor, Tel: (010)62789922, E-mail: [email protected] Supported by National Science&Technology Major Project (No.2009ZX04014–082)

Manuscript received 2010–06–13, in revised form 2010–08–10

ABSTRACT In view of the numerical inverse identification of constitutive models, a forward numer- ical modelling of Gleeble tension tests is conducted. A coupled electrical–thermal–mechanical model is proposed for the resolution of electrical, energy and momentum conservation equations by means of finite element method. In momentum equation, the mixed rheological model in multi–phase region (e.g. δ–ferrite and γ austenite (δ+γmixture)) is developed to consider the δ/γ phase transformation phenomenon for micro–alloyed low carbon steel at high temperature. Experimental and numerical results reveal that significant thermal gradients exist in specimen along longitudinal and radial direc- tions. Such thermal gradients will lead to phase fraction gradient in specimen at high temperature, such asδ fraction gradient or liquid fraction gradient. All these gradients will contribute to the het- erogeneous deformation of specimen and severe stress non–uniform distribution, which is the major difficulty for the identification of constitutive models, especially for the simple identification method based on nominal stress–strain. The proposed model can be viewed as an important achievement for further inverse identification methods, which should be used to identify constitutive parameters for steel at high temperature in the presence of thermal gradients.

KEY WORDS Gleeble tension test, micro–alloyed low carbon steel, numerical modelling

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1000 1100 1200 1300 1400 1500

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Fig.6 Temperature distribution in the central part of ten- sile specimen at temperature (TC0) of 1300 (unit: )

-30 -20 -10 0 10 20 30 0.0

0.2 0.4 0.6 0.8 1.0

Grip contact region

Strainrate,10

-3s

-1

Distance to mid-length transverse-section, mm Grip contact region

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Fig.7 Strain rate distribution along axis at the instanttms, grip velocity of 0.01 mm/s and temperature (TC0) of 1300