20CrMnTi齿轮钢中TiN夹杂物的特征与分布  

Characteristics and distribution of TiN inclusions in 20CrMnTi gear steel

作　　者：李尧 成国光 鲁金龙 孙军[3] LI Yao;CHENG Guo-guang;LU Jin-long;SUN Jun(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;Technology Center,Baowu Group Guangdong Shaoguang Iron and Steel Co.,Ltd.,Shaoguan 512123,Guangdong,China;Technology Center,Xining Special Steel Co.,Ltd.,Xining 810005,Qinghai,China)

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]宝武集团广东韶关钢铁有限公司技术中心,广东韶关512123 [3]西宁特殊钢股份有限公司技术中心,青海西宁810005

出　　处：《中国冶金》2020年第12期28-34,共7页China Metallurgy

基　　金：国家自然科学基金资助项目(51874034)。

摘　　要：为了研究含钛齿轮钢中TiN夹杂物的析出与控制,利用扫描电镜对20CrMnTi齿轮钢两个端淬试样中TiN夹杂的分布与形貌进行了观察,通过夹杂物自动分析系统统计了试样中TiN夹杂的尺寸、数量,建立了数学模型,对试样中TiN夹杂的析出与长大进行了计算。结果表明,较高钛含量的试样凝固过程中TiN析出更早,析出量也更大,由于析出了更多数量的TiN夹杂,从而使得析出TiN夹杂的最终尺寸更小,当TiN夹杂的数量密度由37.28增加为58.65个/mm^(2)时,TiN平均尺寸由2.33减小为1.49μm。通过在凝固过程中为TiN夹杂提供充足数量的氧化物颗粒作为析出核心,提高异质形核率,从而增大TiN的析出数量,就可以降低析出TiN的整体尺寸,这为含钛齿轮钢中TiN夹杂物的控制提供了一种新的思路。In order to study the precipitation and control of TiN inclusions in Ti-bearing gear steel,the distribution and morphology of TiN inclusions in two quenched specimens of 20 CrMnTi gear steel were observed by means of scanning electron microscope,the size and quantity of TiN inclusions in samples were counted by the inclusion automatic analysis system,and a mathematical model was established to calculate the precipitation and growth process of TiN inclusions in experimental samples.The results showed that TiN inclusions precipitated earlier and the precipitation volume fraction was larger in the sample with higher Ti content during solidification,and as a result of more TiN inclusions precipitated out,the final size of precipitated TiN inclusions became smaller.When the quantitative density of TiN particles in samples increased from 37.28 to 58.65 mm^(-2),the average equivalent diameter decreased from 2.33 to 1.49μm.By providing a sufficient number of oxide particles as the precipitation core of TiN inclusions during solidification,improving the rate of heterogeneous nucleation and significantly increasing the amount of TiN precipitation,the overall size of TiN precipitation can be reduced,which can provide a new idea for the control of TiN inclusions in Ti-bearing gear steel.

关 键 词：20CrMnTi TiN夹杂 三维形貌 模型计算 异质形核 

分 类 号：TG142.1[一般工业技术—材料科学与工程]