Super304H钢650℃时效过程中析出相演化的定量分析  

Quantitative analysis on evolution of precipitates in Super304H steel during aging at 650℃

作　　者：刘天佐 魏玉忠 马芹征 郭凯旋 金晓 张国栋[3] Liu Tianzuo;Wei Yuzhong;Ma Qinzhen;Guo Kaixuan;Jin Xiao;Zhang Guodong(Technical Service Branch,Huadian Power International Co.,Ltd,Jinan Shandong 250014,China;Zouxian Plant,Huadian Power International Co.,Ltd,Zouxian Shandong 273522,China;Suzhou Nuclear Power Research Institute,Suzhou Jiangsu 215004,China)

机构地区：[1]华电国际电力股份有限公司技术服务分公司,山东济南250014 [2]华电国际电力股份有限公司邹县电厂,山东邹县273522 [3]苏州热工研究院有限公司,江苏苏州215004

出　　处：《金属热处理》2019年第12期232-237,共6页Heat Treatment of Metals

基　　金：国家重点研发计划(2017YFB0702200)

摘　　要：通过SEM、TEM等手段对在650℃进行500、1000、3000、5000和8000 h长时高温时效后的Super304H奥氏体耐热钢的第二相结构进行定量表征。结果表明,经过长时间时效处理后,最主要的析出相是晶内弥散分布的纳米级富Cu相、少量MX相和晶界上少量M23C6相。随着时效时间的增加,M23C6相的平均尺寸从时效500 h的小于150 nm增加到8000 h的近300 nm,富Cu相的平均尺寸从时效500 h的约15 nm增加到8000 h的40~50 nm,MX相的尺寸在时效过程中一直保持在100 nm以内。通过对富Cu相激活能拟合计算发现其在Super304H奥氏体耐热钢中的长大激活能接近18Cr-8Ni不锈钢中的理论值,证明富Cu相颗粒的长大主要由Cu原子在基体中的扩散所控制。The secondary phase structure of Super304H austenitic heat-resistance steel after aging at 650℃for 500,1000,3000,5000,and 8000 h respectively was quantitatively characterized by using SEM and TEM.The results show that after long-term aging,the most important precipitated phases are intragranular dispersive nano-scale Cu-rich phase,with a small amount of MX phase,and a small amount of M23C6 phase at the grain boundary.With the increase of the aging time,the average size of the M23C6 phase increases from less than 150 nm at 500 h to nearly 300 nm at 8000 h.The average size of the Cu-rich phase increases from about 15 nm at 500 h to nearly 50 nm at 8000 h,and the size of the MX phase Keeps within 100 nm during aging.It is found by fitting that the growth activation energy of the Cu-rich phase in Super304H steel is close to the theoretical value in 18Cr-8Ni stainless steel,which proves that the growth of Cu-rich particles is mainly controlled by the diffusion of Cu atoms in the matrix.

关 键 词：Super304H耐热钢 析出相 时效 富Cu相 长大机制 

分 类 号：TH142[一般工业技术—材料科学与工程]