论文部分内容阅读
P280GH碳锰钢用于制造压水堆核电站核岛蒸汽系统和辅助系统管道,其在280~350℃的长时服役过程中易于出现老化现象。为了研究其热老化机理,在400℃温度下进行了P280GH碳锰钢的10 000 h的加速热老化试验。测定了不同老化时间下铁素体和珠光体的显微硬度、试样拉伸性能和冲击性能。结果表明,铁素体和珠光体的显微硬度随老化时间的增长而逐渐减小;老化时间少于300 h时,拉伸强度和屈服强度随老化时间增长而增加,老化时间大于300 h后,抗拉强度逐步降低,屈服强度缓慢降低;冲击吸收功随老化时间的增加而减小。上述力学性能变化与热老化过程中的珠光体形貌变化及铁素体中的位错移动有关。
P280GH carbon-manganese steel is used to make the nuclear island steam system and auxiliary piping of PWR nuclear power plants, which are prone to aging during long service life at 280 ~ 350 ℃. In order to study its thermal aging mechanism, the accelerated aging test of 10 000 h of P280GH carbon-manganese steel at 400 ℃ was carried out. The microhardness, tensile and impact properties of ferrite and pearlite under different aging time were measured. The results show that the microhardness of ferrite and pearlite decreases with the increase of aging time. When the aging time is less than 300 h, the tensile strength and yield strength increase with aging time, and the aging time is longer than 300 h , The tensile strength gradually decreases and the yield strength decreases slowly. The impact absorption power decreases with the aging time. The change of mechanical properties is related to the change of pearlite morphology and the dislocation movement in ferrite during the thermal aging process.