摘要
研究了终冷温度和等温时间对中低碳纳米贝氏体钢显微组织演变的影响。结果表明,实验钢采用缓冷至低于Ms0温度后等温工艺,可获得纳米贝氏体钢。随着终冷温度降低,贝氏体增多,残留奥氏体的含量先升高后降低,300℃终冷,组织中未转变奥氏体大量转变为贝氏体,残留奥氏体减少,贝氏体板条最细,可达200~300 nm;300℃等温,随着等温时间增加,碳含量不同的未转变奥氏体,在低于实验钢Ms0温度高于未转变奥氏体Ms’温度时,相继发生贝氏体转变,组织中贝氏体的含量不断升高,等温5 h后,贝氏体含量高于75%。
Effect of final cooling temperature and isothermal time on microstructure evolution of a medium-low carbon nanostructured bainitic steel was studied. The results show that the nano-bainitic steel is obtained by isothermal process followed by cooling slowly to below Ms0. With final cooling temperature decreasing,the volume fraction of bainite in the steel increases,whereas retained austenite increases at first and then decreases. When final cooling temperature is 300 ℃,a large number of austenite transforms into bainite with the finest bainite laths,up to 200-300 nm,and retained austenite decreases. With the increasing isothermal time at 300 ℃,unchanged austenite with different carbon content transforms into bainite sequentially in the range between Ms0 and Ms',and volume fraction of bainite is more than 75% at 300 ℃ for 5 h.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第2期119-124,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51274036)
关键词
终冷温度
等温时间
贝氏体
残留奥氏体
final cooling temperature
isothermal time
bainite
retained austenite.
