Determination and analysis of CCT curve of a high strength steel

被引：0
|
作者：
Wang X. [1 ]
Li H. [1 ]
Tang W. [2 ]
Luo D. [2 ]
Liu D. [2 ]
Li Y. [3 ]
Peng N. [2 ]
Xiong X. [2 ]
机构：
[1] School of Materials Science and Engineering, Central South University, Changsha
[2] Xiangtan Iron & Steel Co. Ltd. of Hunan Valin, Xiangtan
[3] Hengyang Valin Steel Tube Co. Ltd., Hengyang
来源：
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | 2021年 / 52卷 / 04期
关键词：
CCT curve; Continuous cooling; High strength steel; Microstructure; Thermal simulation;
D O I：
10.11817/j.issn.1672-7207.2021.04.006
中图分类号：
学科分类号：
摘要：
The dilatometric curves of hot-rolled steel continuously cooled to room temperature at different cooling rates were measured by Gleeble-3500 thermal simulator. Combined with microstructure observation and hardness test, the CCT curve of a high strength steel was plotted, and the influence of different cooling rates on microstructure evolution and hardness was analyzed. The research results show that when the cooling rate is less than 0.2℃/s, ferrite transformation and bainite transformation mainly occur, and the transformation product is a mixed structure of pre-eutectoid polygonal ferrite+upper bainite+granular bainite; when the cooling rate is in the range of 0.5-1.0℃/s, bainite transformation occurs mainly. The transformation product corresponding to the cooling rate of 0.5℃/s is mainly upper bainite, and the transformation product corresponding to the cooling rate of 1.0℃/s is lower bainite; when the cooling rate is 1.0-5.0℃/s, bainite+martensite transformation occurs, and the transformation product is a mixed structure of lower bainite+lath martensite; when the cooling rate is greater than or equal to 5.0°C/s, martensite transformation mainly occurs, and the microstructure is mainly lath martensite. When the cooling rate is less than 5.0℃/s, the hardness increases significantly with the increase of cooling rate. When the cooling rate is greater than 25.0℃/s, the hardness changes little. © 2021, Central South University Press. All right reserved.
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页码：1090 / 1098
页数：8
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