Processing and properties of nanostructured oxide dispersion strengthened (ODS) steels for nuclear applications


  报告题目:Processing and properties of nanostructured oxide dispersion strengthened (ODS) steels for nuclear applications 

  报告人:张洪涛  博士  英国拉夫堡大学 




  Oxide-dispersion-strengthened (ODS) ferritic steels are promising candidate materials in fission and fusion power plantsdue to their relatively stable high temperature mechanical properties and comparative resistance to neutron irradiation. In this talk, two important topics about ODS steels will be presented: (1) Understanding of oxide-based nano-precipitate (nanocluster) formation during ODS processing.The superior performance of ODS steels over conventional equivalents is attributed to the presence of nanosized oxide dispersoids. Therefore, above understanding is crucial for optimisation of alloy-process combinations. The evolution of phases in ODS ferritic steel during mechanical alloying and subsequent annealing was studied by high resolution powder neutron diffraction, with emphasis on the kinetics of oxide-based nano-precipitate formation. (2)Alternative processing routes for ODS steels. Current mainstream processing technique of ODS steels is hot isostatic pressing (HIP), in which both high temperature (1100 - 1200oC), high pressure (~200 MPa), and long soaking time (~4 h) are employed. Thus, the manufacturing cost of ODS steels is very high. Alternative cost-effective processing routes for ODS steels to HIP are urgently needed. Both solid-state processing (spark plasma sintering) and liquid-state processing (spray forming) were explored in this work. The results show their potential as cost-effective approaches for manufacturing of ODS steels.