Materials Congress '98- Frontiers in Material Science and Technology, organised by the Institute of Materials was held from the 6 to 8 April 1998 at the Royal Agricultural College, Circencester. This event which was attended by more than 450 delegates from academia and industry consisted of technical sessions dealing with materials issues involving rubbers, polymers, composites ceramics, ferrous and nonferrous metals and alloys in applications ranging from medical prosthesis two advanced powerplant engineering. These proceedings contain the 10 most important papers presented in the session of the Congress concerned with materials for high temperature powerplant and process plant applications organised by the institute of Materials High Temperature Materials Performance Committee. The selected papers are largely in the form of critical reviews which not only highlight the development of materials to meet specific applications but also comment on solutions used for both current and future applications. These reviews not only discussed the evolution of advanced materials for high temperature power and process plant applications but also indicate the developments in materials which must take place to achieve the higher efficiency and environmentally acceptable plant for the 21st century and beyond.