Materials for high temperature applications. In addition to the above common general patterns, resistance to high temperature has been recognised as a requirement for materials in a wide spectrum of energy technologies. First, irrespective of the origin of the heat, the efficiency of thermodynamic cycles operating between two heat reservoirs is improved by increasing the temperature of the hot one. Moreover, some energy production systems simply inherently require high temperature in order to function because of the physical-chemical processes involved. Thus, low carbon energy technologies as different from each other as fuel cells and hydrogen, concentrated solar power, bioenergy, geothermal, GenIV nuclear fission, and fusion, find commonalities in the need to operate at temperatures above, and sometimes well above, 400°C. During the transition to a fully low-carbon economy, this problem affects also clean fossil fuel plants, which will as well need to operate at the highest temperature possible to increase efficiency and minimize emissions. In this context it is worth mentioningthat The European Creep Collaborative Committee (ECCC)72 was formed in 1991 to co-ordinate Europe-wide development of creep data for high temperature plants. ECCC has probably the largest and most complete set of creep data in Europe for parent materials and welds and issues regularly guidelines on data generation and assessment methods. In 2017 France decided to rejoin after 10 years absence and ECCC started a new activity for nuclear applications focusing on 316SS and long-term creep. Temperatures in excess of 400°C, approaching and sometimes even exceeding 1000°C, together with thermal cycles imposed by power fluctuations, inflict severe thermomechanical stresses on the plant components. This requires the use and development of materials that should be proven to maintain their integrity and properties for a sufficiently long time at high temperature and/or when subject to thermomechanical fluctuating loads, within reasonable costs. Moreover, high temperature operation requires efficient cooling, leading to the production of superheated steam or to the use of alternative coolants like liquid metals, molten salts or gases, to which materials will have to be exposed. Environmental degradation due to salt water also affects other technologies, such as off-shore wind turbines or ocean energy. Thus materials need to be also resistant to the attack of these environments. The components that are mainly affected by high temperatur...
