【摘要】 研究了中温抗氢钢125Cr—05Mo的回火析出相及其对抗氢蚀能力的影响.碳萃取复型的透射电镜观察显示，随回火温度升高，碳化物析出量增加，颗粒粗化.520和620℃回火析出物几乎全部为M3C;670℃回火析出物以M3C为主并含有少量M23C6；710℃回火主要析出M23C6，包含少量的M3C．扫描电镜观察表明，充氢之后，经620℃回火的试样发生了严重的氢腐蚀，并导致强度和硬度的大幅度下降；经520℃回火的试样在充氢后抗拉强度值下降较多；670和710℃回火试样的各项力学性能变化不大，表现了良好的抗氢蚀能力.620℃回火时沿晶界析出大量不稳定的M3C，以及在碳化物转化过程中出现的富C贫Cr区域，导致材料的氢蚀破坏.更多还原

【Abstract】 Studies were made on the tempering precipitates and their effects on hydrogen attack (HA) resistance of the medium-temperature HA-resistant Steel 1.25Cr-0.5Mo. It was shown by TEM of carbon extraction replicas that, with increasing tempering temperature, more carbides were precipitated and coarsened. When tempered at 520℃ and 620℃, almost only M3C was precipitated. When tempered at 670℃, M3C was the main precipitate with a small amount of M23C6. While tempered at 710℃, M23C6 was the main precipitate with a small amount of M3C. It was observed by SEM that,after charging hydrogen, samples tempered at 620℃ were seriously attacked by hydrogen, which resulted in great drop of strength and hardness.While no apparent HA phenomenon was observed for samples tempered at 520℃, 670℃ and710℃, but rupture strength of samples tempered at 520℃ was greatly decreased. It is related that large quantity of unstable M3C precipitated along grain boundaries, and the C-rich and Cr-poor regions for the sample tempered at 620℃ appeared, resulted in the HA degradation of the material.更多还原