超超临界机组叶片钢KT5331晶粒长大行为  

Grain growth behavior of blade steel KT5331 for ultra-super critical units

作　　者：李俊儒[1] 宋明强[1] 龚臣[1] 陈列[2] 佐辉[2] 刘雅政[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]西宁特殊钢股份有限公司,西宁810005

出　　处：《工程科学学报》2015年第12期1570-1574,共5页Chinese Journal of Engineering

基　　金：'十二五'国家高技术研究发展计划资助项目(2012AA03A502)

摘　　要：通过在不同温度下等温奥氏体化,研究KT5331钢奥氏体晶粒长大行为,并探讨析出相对奥氏体晶粒长大行为的影响机理.研究表明,KT5331钢奥氏体晶粒长大可分为三个阶段：1075℃以下,由于含W和Nb的析出相钉扎作用,晶粒长大缓慢;1075℃以上,含W和Nb的析出相溶解,钉扎作用减弱,随加热温度和保温时间延长晶粒迅速长大;1225℃及以上,δ铁素体析出,晶粒尺寸随加热温度升高而急剧减小.通过拟合分别得到晶粒粗化温度以下（950~1075℃）和晶粒粗化温度以上（1100~1200℃）的晶粒长大模型.The austenite grain growth behavior of KT5331 steel and the effect of precipitates on the austenite grain growth were studied by isothermal austenization at 950-1280 ℃. The results show that the austenite grain growth process can be divided into three stages. Due to the pinning effect of precipitates containing W and Nb,the austenite grains grow slowly below 1075 ℃. Most of the precipitates dissolve above 1075 ℃,leading to the austenite grains coarsened. When the temperature rises to 1225 ℃,δ-ferrite precipitates and results in austenite grain refinement with increasing temperature. The austenite grain growth models below and above the coarsening temperature 1075 ℃ were established by numerical fitting.

关 键 词：耐热钢 奥氏体 晶粒长大 数学模型 

分 类 号：TG142.73[一般工业技术—材料科学与工程]