Duplex stainless steels (DSS) suffer from thermal aging embrittlement after long-term service in the temperature range of 280-320°C, leading to severe deterioration of mechanical properties and corrosion resistance. It is now well known that the typical microstructural evolutions of the thermally aged DSS are the spinodal decomposition and the G-phase precipitation in ferrite. This review provided a comprehensive analysis of the microstructure, mechanical characteristics, and corrosion resistance of the long-term thermally aged DSS. The principles for how the microstructural evolutions affect the performance of the thermally aged DSS were also highlighted. Some controversial issues such as the formation mechanism of G-phase and its role in the evolutions of material properties were discussed. In addition, a comprehensive review of the recovery behaviors of thermal aging embrittlement was also provided. At last, the limitations of present researches and future research directions of the practical engineering application requirements were summarized.

双相不锈钢（DSS）在280-320°C的温度范围内长期使用后会遭受热时效脆化，从而导致机械性能和耐蚀性严重降低。众所周知，热时效DSS的典型微观结构演变是旋节线分解和铁素体中的G相析出。这篇综述提供了对长期热老化DSS的微观结构，机械特性和耐腐蚀性的全面分析。还着重介绍了微观结构演变如何影响热老化DSS性能的原理。讨论了一些有争议的问题，如G相的形成机理及其在材料性能演变中的作用。此外，还提供了对热老化脆化的恢复行为的全面综述。最后，总结了当前研究的局限性和实际工程应用需求的未来研究方向。