Oxidation/carburisation of Fe-9Cr-1Mo in carbon dioxide, Roger Reed, Lecture 24 of 25
Channel: bhadeshia123
Date: 2021-12-17

Lecture 24, by Professor Roger Reed,  University of Oxford,   in the series "Steel Research: A global journey",  organised by Adreil Wong, Dominik Dziedzic and Steve Ooi to mark the retirement of Harry Bhadeshia. 

Numerical modelling of the degradation of P92  martensitic steels in gas 70% CO2-30%H2O at 550 C is described, emphasising the formation of duplex oxide scale and internal carburisation.  Numerical models with varying levels of sophistication are presented for the evolution of multiphase regions, subject to a Robin-type boundary condition representing a Boudouard surface reaction. The surface reaction kinetics at the spinel/substrate interface and the carbon transport kinetics in the substrate result in unusual carbon concentration profiles, measured here by glow-discharge optical emission spectroscopy (GDOES). Analysis of experimental data indicates that moisture decreases the rate of the surface reaction, despite higher carbon activity of the gas.

https://www.phase-trans.msm.cam.ac.uk/