Zihao Wang

Breaking frontiers in stress corrosion cracking of nickel-based alloys from the perspective of diffusible hydrogen

Nuclear energy is forecast by the European Commission to make a significant contribution to achieving a low-carbon, affordable energy, enhancing energy security during the development of renewables. However, stress corrosion cracking (SCC) is one of the biggest obstacles, as it induces unexpected failure to nuclear power plant components, threatening operational safety. Mitigating SCC requires a thorough understanding of its mechanisms, of which the current understanding is limited. In recent years, it has found that diffusible hydrogen plays a critical role in the evolution of SCC, which is beyond the existing understanding. Therefore, this project aims to uncover new SCC mechanisms in Ni-based alloys and stainless steel (materials used in nuclear power plants) from the perspective of the role of diffusible hydrogen, based on the good foundation of our previous work. The multi-scale experimental approach will focus on in-situ materials characterisation of Ni-based alloys and stainless steel during mechanical testing with in-situ hydrogen charging. The results have the potential to provide practical suggestions and guidance to our end-users for producing alloys with higher SCC-resistance for a safer utilisation of nuclear energy.

Characterising crack tip to understand SCC mechanism

Characterising crack tip to understand SCC mechanism (a) HAADF image at the GB of the Ar-exposed specimen; and the related (b, c, and d) magnified TEM-BF, HAADF, and O intensity images of the oxide tip of the GB; (e) HAADF image at GB for the H-exposed specimen, and the related (f) magnified TEM-BF image of the oxide tip of the GB.


Selected Publications