为了实现火电机组高效、清洁利用能源，高参数、大容量的超超临界机组得以发展。火电机组蒸汽温度和压力的进一步提高，对材料的性能提出了更严苛的要求。归纳了目前超超临界机组不同部件耐热钢的选用，总结了耐热钢使用过程中存在的主要问题，概述了700 ℃超超临界机组的开发对材料性能的需求。

The ultra supercritical unit with the high temperature parameters and the large capacity has been developed in order to achieve the high efficiency of thermal power units and the clean energy use. However, the steam temperature and pressure of thermal power units have been further increased, which present more stringent requirements for the material performance. This paper summarized the selection approach of heat resistant steel for the different parts in ultra supercritical units, as well as the existing problems in the using process of heat resistant steels. Furthermore, the development tendency and the material requirements were reviewed for 700 ℃ultra supercritical units.