APPROACHES TO DEVELOPMENT OF STEELS AND MANUFACTURING TECHNOLOGIES FOR FUSION REACTORS

摘要

The development of radiation resistant steels for fusion reactors would rely heavily on the rich experience gained in the commercialization of fast reactor core component materials, in the last three decades. The extrapolation of behaviour of materials from fission to fusion environments is not straight forward, owing to the wide differences in the service exposure conditions. However, the knowledge base developed in a wide spectrum of fields for the fast reactor technology so far will shorten the time span for development of newer materials. The paper discusses the evolution of various austenitic, ferritic, ferritic/martensitic and Oxide Dispersion Strengthened (ODS) steels through optimisation of chemical composition, fabrication processes and heat treatment to achieve required material properties for fast reactor applications. Recent results on characterization of Ti-modified austenitic stainless steels with electron microscopy and positron annihilation are discussed in the context of role of minor elements on void swelling and mechanical properties. Artificial neural network models, finite element simulation and phase evolution studies are discussed in the context of fabrication of fusion reactor components. The importance of complex Y-Ti-O nano clusters for enhanced creep strength at elevated temperatures in ODS alloys and the role of defects formed during mechanical alloying are discussed.