P92 steel is candidate material for application in reactor pressure vessels in nuclear power plants. In present investigation, Laves phase evolution (at 650 °C) with varying ageing time (upto 3000 h) in P92 steel and their effect on mechanical properties have been investigated. During thermal ageing, the microstructure analysis showed the evolution of Laves phase that degrades the strength of P92 steel. The formation of Laves phase was observed after the thermal ageing of 720 h and it showed higher coarsening rate in ageing time range of 720 h −1440 h. The Laves phase formation was also confirmed by the XRD analysis, and line mapping. The strength and ductility decreased as a result of deprivation of solid solution strengthening and formation of Laves phase. The hardness of P92 steel was also affected by ageing time but less pronounced as compared to strength. Charpy toughness was also reduced continuously with increase in ageing time as a result of thermal straining of particles and Laves phase formation.

P92钢是用于核电站反应堆压力容器的候选材料。在目前的研究中，研究了P92钢在不同时效时间（长达3000 h）下Laves相的演变（在650°C时）及其对机械性能的影响。在热时效过程中，显微组织分析表明，拉维斯相的演变降低了P92钢的强度。在720 h的热老化后观察到Laves相的形成，并且在720 h -1440 h的时效时间范围内表现出较高的粗化率。Laves相的形成还通过XRD分析和线图确认。强度和延展性的降低是由于缺乏固溶强化和Laves相的形成。P92钢的硬度也受时效时间的影响，但与强度相比却不太明显。由于颗粒的热应变和拉夫斯相的形成，夏比韧性也随着老化时间的增加而连续降低。