稀土钇和铈对321不锈钢中钛类夹杂物的改性作用  

Modification of titanium inclusions in 321 stainless steel by yttrium and cerium

作　　者：何晓妍 胡晓军[1] HE Xiaoyan;HU Xiaojun(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学绿色低碳钢铁冶金全国重点实验室,北京100083

出　　处：《江西冶金》2024年第2期106-115,共10页Jiangxi Metallurgy

摘　　要：通过在321不锈钢熔炼过程中分别添加不同含量的稀土元素钇(Y)和铈(Ce),研究321不锈钢中钛类夹杂物的热力学特征,考察了稀土元素种类及含量对钢中钛类夹杂物成分及形貌的影响。结果表明,未添加稀土元素时,321钢液中典型夹杂物为TiN和以Al_(2)O_(3)为核心的Al_(2)O_(3)-TiN复合夹杂物。向钢液中添加稀土元素,当Y添加量为5.0×10^(-6)(质量分数,下同)时,钢液中的典型夹杂物为Al_(2)O_(3)-Y_(2)O_(3)和部分未被改性的Al-O复合夹杂物,随着Y元素含量增加,Al_(2)O_(3)夹杂物被逐渐改性为含钇氧化物,当Y添加量为4.7×10^(-5)时,钢液中的典型夹杂物为Y_(2)O_(3)-TiN复合夹杂物;当Ce添加量为5.0×10^(-6)时,钢液中的夹杂物主要有Ce-O、Ce-Al-O类夹杂物,Al_(2)O_(3)夹杂物不再单独存在。钢液中TiN夹杂物的数量及尺寸随稀土元素添加量的不同而存在差异。添加稀土元素后,TiN数量减少,尺寸减小,当Ce添加量为1.0×10^(-5)时,TiN的数量及尺寸均与Y添加量为4.7×10^(-5)时接近,表明在添加量相近的情况下,Ce对夹杂物的改性效果优于Y。The study investigated the thermodynamic characteristics of titanium inclusions in 321 stainless steel and the impact of rare earth elements,specifically Y and Ce,on the composition and morphology of these inclusions during the steel's melting process.The results showed that in the absence of rare earth elements,the inclusions commonly found in 321 steels were TiN and Al_(2)O_(3)-TiN composite inclusions,where Al_(2)O_(3) served as the core.When adding rare earth elements to the steel,at a Y addition of 5.0×10^(-6)(mass fraction),the steel contained typical inclusions of Al_(2)O_(3)-Y2O_(3) and some unmodified Al-O composite inclusions.As the Y element content increased,the Al_(2)O_(3) inclusions were gradually modified to yttrium-containing oxides.When the Y addition was 4.7×10^(-5),the typical inclusions in the steel were Y2O_(3)-TiN composite inclusion.With the addition of 5.0×10^(-6) Ce,the inclusions consisted mainly of Ce-O and Ce-Al-O,and Al_(2)O_(3) inclusions no longer existed separately.The number and size of TiN inclusions in the liquid steel varied depending on the addition of rare earth elements.The addition of rare earth elements resulted in a decrease in the number and size of TiN.Specifically,when the amount of Ce added was 1.0×10^(-5),the number and size of TiN were similar to those when the amount of Y added was 4.7×10^(-5).Ce appears to have a more effective modification effect on inclusions compared to Y at similar addition amounts.

关 键 词：稀土 321不锈钢 夹杂物 TiN-Al_(2)O_(3) 

分 类 号：TF70[冶金工程—钢铁冶金] TG146.4[一般工业技术—材料科学与工程]