摘要
低钛轴承钢中存在大尺寸TiN夹杂,为分析其来源,基于三种不同的微观偏析模型,计算了凝固过程TiN析出的热力学及长大的动力学,并且采用熟化理论计算加热过程中TiN的尺寸变化。结果表明,TiN在凝固分数超过0.97时析出,降低钢中初始N含量可以推迟TiN的析出;在冷却速率0.5 K/s时,L-S模型、O模型、K模型计算的TiN析出理论半径分别为8.154μm、7.455μm和6.891μm,O模型、K模型计算的结果与试样TiN最大直径14.1μm最为接近。加热熟化过程中TiN尺寸增加仅为纳米级,表明产生于凝固过程中的大尺寸TiN夹杂在加热过程中主要发生分解,而熟化对其尺寸的影响可以忽略。
The large size TiN inclusions were found in low titanium bearing steel.In order to analyze the source,three different microscopic segregation models were used to calculate the thermodynamics of TiN precipitation and growth dynamics during solidificat ion,and the Ostwald maturation theory was used to calculate the change of TiN size during heating process.The results show that TiN precipitates when the solidification fraction exceeds 0.97,and the precipitation of TiN can be delayed by decreasing the initial N content in steel.At the cooling rate of 0.5 K/s,the theoretical radius of TiN precipitation calculated by L-S Model,O Model and K Model are 8.154μm,7.455μm and 6.891μm respectively,Ohnaka and Kobayashi model are closest to the maximum diameter 14.1μm observed in the sample.The size increase of TiN was only nanoscale during the heating process,indicating that the large size of TiN inclusion,which were generated during the solidification process,mainly decompose to small size during heating process,the Ostwald maturation process has little effect on TiN size.
作者
李永超
杨玉丹
吴豪明
卢彩玲
贾名琳
王维
Li Yongchao;Yang Yudan;Wu Haoming;Lu Cailing;Jia Minglin;Wang Wei(Technical Center of Henan Jiyuan Iron and Steel(Group)Co.,Ltd.,Jiyuan 459000,Henan)
出处
《河北冶金》
2022年第4期19-24,共6页
Hebei Metallurgy
