摘要
利用SEM、TEM对宝钢T91钢在500℃、不同持久蠕变应力下的微观组织进行了研究。结果表明,500℃蠕变后,位错明显减少,但马氏体板条、M23C6和MX尺寸稳定,仍具有很好的强化作用,说明在500℃蠕变时T91钢具有很好的组织稳定性;在蠕变试样中观察到了Laves相,其有两种形核点:一种是在高应力(320MPa)下,不受M23C6影响,单独形核;另一种是在低应力(280MPa)下,紧邻M23C6形核。Laves相的出现并没有损害T91钢的蠕变性能,是含Al夹杂物引发了T91钢的失效。
The microstructure evolution of T91 steels from Baosteel under different stress conditions at 500 ℃ was investigated by SEM and TEM. The results show that the density of dislocations decrease obviously, while the martensitic lath,M23C6 and MX bear good stability in size, still have good strengthening effect, which means that the microstructure of T91 steel is very stable when creeps at 500℃. After creep, Laves phases have been found nucleating at two different sites, one kind of site is without the presence of M23C6 under higher stress（320MPa）, the other is adjacent to M23C6 under lower stress（280MPa）. The presence of Laves phases does not harm the creep property of T91 steel, it is the Al-inclusion which can cause the failure of the steels.
出处
《热加工工艺》
CSCD
北大核心
2014年第18期70-72,78,共4页
Hot Working Technology
基金
上海市科委基础研究重点项目(12JC1405000)
