Kinetics of internal oxidation of Fe-Mn-Cr steel alloys

Title

Kinetics of internal oxidation of Fe-Mn-Cr steel alloys

 Author

Ma, Yao (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Materials Science and Engineering)

Contributor

Sloof, W.G. (mentor) ORCID 0000-0003-1443-0813
Mao, W. (graduation committee)

Degree granting institution

Delft University of Technology

 Programme

Materials Science and Engineering

 Date

2017-08-04

 Abstract

Selective oxidation behaviour of Fe-Mn-Cr steel alloys annealed at 950°C in Ar plus 5 vol.% H2 atmosphere under different annealing time and dew points was studied. The Fe-Mn-Cr steel alloys are externally oxidized when annealing at dew point of -45 °C, while internally oxidized at dew points of -10 and 10 °C. The internal oxides formed in the Fe-Mn-Cr steel alloys are (Mn, Fe)O and (Cr, Mn, Fe)3O4. The kinetics of internal oxidation of Fe-Mn-Cr alloys at 950 °C is diffusion controlled and follows parabolic growth rate law. The measured kinetics of internal oxidation of Fe-Mn-Cr alloys and the concentration depth profiles of internal oxides are in good agreement with simulation results. Adding Cr to the Fe-Mn steel alloys decreases the kinetics of internal oxidation. The growth rate of internal oxidation zone can be predicted by a modified Wagner’s internal oxidation model. The external oxides formed during annealing of Fe-Mn-Cr steel alloys cannot be reduced by H2. However, an oxide-free steel surface can be obtained by first forming and then reducing a Wüstite scale.

 Subject

Internal oxidation
kinetics
Fe-Mn-Cr steel alloys
annealing

 To reference this document use:

http://resolver.tudelft.nl/uuid:b4fe5e1f-78c3-4729-bf3c-2f8043f42528

 Embargo date

2017-08-07

 Part of collection

Student theses

 Document type

master thesis

 Rights

© 2017 Yao Ma
Files
PDF Master_Thesis_Yao_Ma_v6_1_.pdf 8.16 MB
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