核岛用P280GH碳锰钢热老化的组织和性能  

Microstructures and properties of nuclear carbon manganese steels P280GH after accelerated aging

作　　者：于辉[1] 翟建伟[1] 张超凡[1] 刘帅帅[1] 刘利刚[1] 

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《钢铁》2017年第9期66-72,共7页Iron and Steel

基　　金：国家自然科学基金资助项目(51275445);河北省自然科学基金钢铁联合基金资助项目(E2014203077)

摘　　要：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 steels used for the nuclear steam system and auxiliary system pipes in pressurized water reactor nuclear power plant are susceptible to thermal aging brittleness during long-term service at its working temperature from 280 to 350 ℃. In order to investigate its thermal aging behavior,P280GH carbon manganese steels have been thermally aged at 400 ℃ for up to 10 000 h. The micro-hardness of ferrite and pearlite phases,conventional tensile properties and impact properties at different aging duration have been measured. The results show that the micro-hardness of ferrite and pearlite gradually decreases with increasing thermal aging time. The tensile strength and yield strength increase within 300 h and then progressively and slightly decrease after 300 h with the long aging time,respectively.The charpy impact energy slightly decreases with the long aging time. The changes of all the above mechanical properties of P280GH carbon manganese steels are associated with the changes of the pearlite morphologies,dislocation configurations in ferrite and precipitates after different thermal aging time.

关 键 词：热老化 P280GH碳锰钢 微观组织 力学性能 位错 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TM623.91[金属学及工艺—金属材料]