Wang Jian, Peng Jun, Liu Lixia, Zhang Fang, Peng Jihua, Tang Hao, Zheng Jie, An Shengli
School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China.
Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices, Inner Mongolia University of Science and Technology, Baotou 014010, China.
Materials (Basel). 2023 Aug 12;16(16):5598. doi: 10.3390/ma16165598.
The morphologies and sizes of TiN inclusions in gear steel 20CrMnTi have a significant impact on its service performance. This paper selects rare earth Ce to modify TiN inclusions in 20CrMnTi. The inclusions are analyzed by SEM (scanning electron microscope), EBSD (electron back-scattered diffraction), EDS (energy disperse spectroscopy), and OTS statistical software, and Thermo-Calc software is used to calculate the inclusion formations. The inclusions of MgAlO-Ce and CeAlO can be formed when rare earth Ce is added into 20CrMnTi, which becomes TiN nucleation core after precipitation. Without the addition of rare earth Ce, square TiN inclusions ranging from 2 to 5 μm account for 60% of the total inclusions in 20CrMnTi. After adding rare earth Ce, the TiN inclusions in 20CrMnTiCe account for 36.7% of the total inclusions. Due to the new phase formations of MgAlO-TiN and CeAlO-TiN with sizes less than 2 μm, the titanium-containing inclusions are refined. Fatigue tests are conducted on the steels before and after the addition of Ce. The average fatigue lives of 20CrMnTi do not reach 10 times, and the deviations between the maximum and minimum fatigue lives are great. Large-sized TiN are the main inclusions that affect the fatigue performance of 20CrMnTi. The average fatigue lives of 20CrMnTiCe exceed 10 times, and the deviations of the fatigue lives are smaller than those of 20CrMnTi.
齿轮钢20CrMnTi中TiN夹杂物的形态和尺寸对其服役性能有显著影响。本文选用稀土Ce对20CrMnTi中的TiN夹杂物进行变质处理。通过扫描电子显微镜（SEM）、电子背散射衍射（EBSD）、能谱仪（EDS）及OTS统计软件对夹杂物进行分析，并利用Thermo-Calc软件计算夹杂物的形成情况。向20CrMnTi中添加稀土Ce时可形成MgAlO-Ce和CeAlO夹杂物，析出后成为TiN形核核心。未添加稀土Ce时，尺寸为2～5μm的方形TiN夹杂物占20CrMnTi中夹杂物总量的60%。添加稀土Ce后，20CrMnTiCe中的TiN夹杂物占夹杂物总量的36.7%。由于形成了尺寸小于2μm的MgAlO-TiN和CeAlO-TiN新相，含钛夹杂物得到细化。对添加Ce前后的钢材进行疲劳试验。20CrMnTi的平均疲劳寿命未达到10次，最大和最小疲劳寿命之间的偏差较大。大尺寸TiN是影响20CrMnTi疲劳性能的主要夹杂物。20CrMnTiCe的平均疲劳寿命超过10次，且疲劳寿命的偏差小于20CrMnTi。
