摘要
通过对比国内某钢厂两种不同成分的Q345E性能发现,添加微合金元素Nb和Ti后Q345E的屈服强度和抗拉强度升高,低温冲击性能降低;利用热力学计算软件Thermo-Calc计算Nb-Ti钢和C-Mn钢的平衡态析出相发现,二者主要区别在于Nb-Ti钢多了(Nb、Ti)(C、N)析出相;同时设计三种不同含量Ti的高强试验钢,进行冲击试验后在扫描电镜下观察断口的微观形貌以及第二相颗粒,发现随着Ti含量的增加,试验钢低温冲击性能降低,断口处存在大量大颗粒第二相粒子聚集分布,能谱分析为(Nb、Ti)(C、N),导致冲击功降低.这说明加Ti后会恶化低合金高强度钢Q345E低温冲击性能,因此需要配合控轧控冷与成分的设计,控制第二相粒子的尺寸.
Comparing the properties of Q345E steels of two different components,it is found that the yield strength and tensile strength of Q345E increase with the additions of microalloying elements Nb and Ti,but the low-temperature impact performance reduces. The results of the equilibrium phase calculation of Nb--Ti steel and C--Mn steel using thermodynamic software Thermo--Calc reveal that the main difference between them is the precipitation of ( Nb,Ti) ( C,N) phase. Furthermore,three titanium containing high-strength test steels were designed to observe the microtopography of the fracture and the second-phase particles of steels after impact test under scanning electron microscopy. With the increase of Ti,the low-temperature impact performance of steels reduced,and a number of large particles were gathered in the fracture,which were found to be ( Nb,Ti) ( C,N) using energy dispersive spectrometer ( EDS) analysis,resulting in reduced impact energy. The results indicate that Ti deteriorates the low-temperature impact performance of low-alloy high-strength steel Q345E;therefore,it is necessary to control the size of the second-phase particles using controlled rolling and cooling or component design.
作者
刘帅
王福明
李永亮
LIU Shuai;WANG Fu-ming;LI Yong-liang(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Technology Center of Tangsteel Company,Hesteel Group,Tangshan 063000,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2018年第S1期41-46,共6页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(51674020)
十三五国家重点研发计划资助项目(2016YFB0300102)
作者简介
通信作者:王福明,E-mail:wangfuming@metall.ustb.edu.cn.
