Download A03-09: Hydrogen effect on grain boundary in Steel Faglærer

A03-09:
Hydrogen effect on grain boundary in Steel
Faglærer:
Medveiledere:
Afrooz Barnoush, [email protected]
Tarlan Hajilou (PhD student, NTNU) and Nousha Kheradmand
The project will be in close collaboration with Kyushu University, the University of Illinois
at Urbana-Champaign, Ruhr-Universität Bochum Germany, Statoil, Aker solution, DNV GL
and enthusiastic students can spend sometimes doing research in partner institutes. The
NTNU NanoLab and MTP Nanomechanical lab will be used intensively during this project.
The required training will be provided. Scanning electron microscope, nanoindentation and
focused ion beam are among the mainly used instruments.
NTNU, Sintef Materials and Chemistry and UiO have established a research collaboration
founded by NFR (Forskningsrådet) to gain a fundamental understanding of the hydrogen
embrittlement through a multi-scale modeling and testing approach with specific focus on
hydrogen grain boundary interaction.
The aim of the project work is to collaborate
within a part of the research collaboration
dealing with experimental verification of
modeling outcomes where hydrogen effect
on the grain boundary under stress is studied
using bicrystal cantilevers cut by focused
ion beam (FIB) in nanolab at NTNU. The
newly upgraded state of the art standalone
nanomechanical testing platform from
Hysitron, TI950 in combination with the
special electrochemical cell developed at
NTNU will be used to bend the bicrystalline
cantilevers in situ under electrochemical
control. With the application of cathodic
polarization, it is possible to charge the
cantilevers with H. The small size of the
500nm
2μm
cantilevers assures a uniform concentration
of H and fast saturation of the grain
boundary with H. The results will be compared to similar cantilevers deformed in H free
condition. This makes it possible to quantitatively measure the grain boundary cohesion
energy and the effect of H.