Page 30 - Thetha Issue 7

WATCH THIS SPACE: PHD RESEARCH

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Dr Hlanganani Nyembe
There is plenty of fascinating research taking
place at Nelson Mandela University and,
always, it is about working in service of society,
writes Gillian McAinsh
Space

Could Physics be Answer for Eskom Woes?

PhD in Physics from Nelson Mandela that could be used as indicators of creep damage.
University, in collaboration with the “I used state-of-the-art microscopes at the
Eskom Power Plant Engineering Centre for High Resolution Transmission Electron
A itute, could help Eskom keep part Microscopy (HRTEM) at Mandela University
Inst
of its expensive maintenance project in check. to reveal and study nano-sized features in the
Dr Hlanganani Siphelele Nyembe, who structure of these samples.”
graduated in April 2023, explains that his PhD Dr Nyembe says he was grateful to have had
research project method could help supplement Dr Johan Westraadt and his team as promoters
the way Eskom power stations manage their for his PhD.
costly turbine rotors. His research also included developing a
His project focused on rare samples microstructural-based creep life assessment of
extracted from 1CrMoV steel rotors (used for 1CrMoV steam turbine rotors used in power
the high-pressure turbine rotors in South Africa’s plants. This, he says, could help supplement the
older power stations). way Eskom power stations manage their costly
“These high-pressure turbine rotors are turbine rotors.
critical components of power plants, and His method is not only applicable to 1CrMoV
their replacement has significant economic steel components, but may be modified
implications,” says the power industry graduate. to evaluate the life of other power plant
Specifically, he says, it is important to components.
avoid “creep failure”. This is when a material is In short, this research might contribute to
subjected to high temperatures and pressures huge potential economic savings by replacing
over a long time, and it deforms irreversibly until power plant components only when they have
it breaks. reached their end-of-life criterion.
“To prevent creep failure, it is essential to His work has been recognised with an award
monitor creep behaviour of turbine rotors and from the Microscopy Society of Southern Africa,
ensure that they do not exceed their creep limit.” and he showcased his work at the Microscience
In his research, Dr Nyembe used samples Microscopy Congress incorporating EMAG
from Eskom to identify microstructural features conference held in the UK in July.

28 | Thetha Edition 7 | 2023