超超临界火电机组用T23钢的高温蠕变断裂行为

High Temperature Creep Rupture of T23 Steel Used for Ultra-Supercritical Power Plant

通过研究和分析超超临界火电机组用T23钢持久试样的断口形貌及其在600℃高温蠕变过程中的组织演变,探讨了不同应力水平下T23钢的蠕变断裂机制。研究结果表明,T23钢在高应力条件下的蠕变断裂机制类似于常温下典型的韧性断裂,蠕变空洞主要形核于晶内的夹杂物处;而在低应力条件下的蠕变断裂机制表现为脆性沿晶断裂,蠕变空洞则主要形核于晶界第二相处。

The fracture morphology of creep rupture tested samples and microstructural evolution was investigated at 600 ℃, and the creep rupture mechanism of a T23 steel used for ultra-supereritcal power generations was discussed under different stress levels. The results show that, under condition of high stress level, the creep rupture mecha- nism is similar to the ductile fracture at room temperature, and the cavities nucleate mostly at sites of the inclusions, behaving intragranular fracture. However, under low stress level, the creep rupture mechanism is brittle fracture occurred along the grain boundary, and the cavities nucleate mostly at sites of the second-phases, behaving interg ranular fracture.