Selective oxidation mechanisms of Al-Mn alloyed steels

Description de l'offre

Country:

FRANCE

Region:

LORRAINE

Sector:

ArcelorMittal Europe - Flat Carbon

Unit:

Site:

R & D Process Maizières les Metz

Field of activity:

Research and Development / Metallurgy Innovation

Title of internship:

Selective oxidation mechanisms of Al-Mn alloyed steels

Subject of the internship:

During recrystallization annealing of high alloyed steels under N2-H2 atmosphere, alloying elements like Al and Mn segregate to the steel surface and form oxide particles or films. Such oxides disfavour the surface wetting by liquid Zn and can lead to the formation of coating defects during the hot dip galvanizing. The internship objective is, therefore, to understand the mechanisms of Al and Mn diffusion and oxide films growth at different conditions of recrystallization annealing (effect of elements concentration, annealing temperature and duration, atmosphere dew point). This knowledge will lead us to manage properly the steel surface chemistry during the annealing and its coatability by zinc alloy.

- Literature synthesis on selective oxidation and diffusion of Mn and Al in steel matrix
- Experimental work on - Validation of experimental protocol to simulate recrystallization annealing at different dew point - Study of the effect of elements content on selective oxidation (binary FeAl and ternary Fe-Mn-Al systems) - Study of the dew point effect on selective oxidation of FeAl and FeMnAl system. - Study of the annealing temperature and duration effect on oxides growth (covering yield and surface chemistry ) - Surface characterization by SEM, Auger-FEG, XPS, GDOES - Some in-situ experiments (annealing – XPS) for validation of oxides surface chemistry.
- Interpretation of results and conclusions on oxidation kinetics, elements diffusion, internal/external oxidation competition in function of oxygen partial pressure

Profil recherché

Applicant Profile:

ECP, PHELMA, ENSMN, EEIGM, UPMC, RWTH, MPI - Physico-chemistry, Chemistry - Motivation for accurate experimental work - English, French

Education:

Physico-chemistry, Chemistry

Level of education:

MASTER (Bac+4/5)

Duration of the internship:

6 months

Period of the internship:

February-March 2017

Managers of the internship:

Ghassan GHAZAL
Tel:
Email: ************@*******.**

Comments:

To apply please contact Alexey Koltsov : ************@*******.**

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