稀土对Ni-Al系马氏体时效钢中夹杂物的改性作用  

Modification of inclusions in Ni-Al maraging steels by rare earths

作　　者：田方铖 高雪云[1,2] 曹悦 邢磊 华连庚[3] 王海燕 Tian Fangcheng;Gao Xueyun;Cao Yue;Xing Lei;Hua Liangeng;Wang Haiyan(School of Materials and Metallurgy,Inner Mongolia University of Science&Technology,Baotou 014010,Inner Mongolia,China;Guangdong Guangqing Metal Technology Co.,Ltd.,Yangjiang 529533,Guangdong,China;Inner Mongolia First Machinery Group Co.,Ltd.,Baotou 014010,Inner Mongolia,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]广东广青金属科技有限公司,广东阳江529533 [3]内蒙古第一机械集团有限公司,内蒙古包头014010

出　　处：《钢铁钒钛》2024年第6期151-158,共8页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金(51961030,52161008);中央引导地方科技发展资金项目(2022ZY0072);内蒙古自治区直属高校基本科研业务费项目(2023QNJS006);阳江市合金材料与五金刀剪重点产业人才振兴计划专项基金(RCZX2022020)。

摘　　要：钢中的非金属夹杂物对超高强度钢的塑韧性具有重要的影响。在Fe-Ni-Al系马氏体时效钢中加入稀土La、Ce元素,通过扫描电子显微镜及能谱仪(SEM-EDS)与电子探针(EPMA)分析结合FactSage热力学计算,研究了不同稀土元素对钢中非金属夹杂物的变质机理。结果表明,马氏体时效钢中加入稀土元素后形成了含稀土的RE-O-S和RE-Al-O,抑制了Al_(2)S_(3)的形成,对AlN夹杂物的形成没有明显影响,夹杂物经稀土改性后形状由条状和不规则的几何形状转变为接近球状。热力学计算结果表明,添加稀土元素后,钢液中可能形成的夹杂物热力学稳定性大致为REAlO_(3)→Al_(2)O_(3)→稀土硫化物→AlN。加入稀土后,在高温熔融态下钢液中RE_(2)O_(3)和Al_(2)O_(3)就已稳定存在,并且随着冷却温度的降低,钢中的夹杂物按REAlO_(3)→RE_(2)O_(2)S→RES的顺序逐渐析出,且稀土La和Ce的夹杂物演化路径基本相同。Non-metallic inclusions in steel have an important influence on the ductility and toughness of ultra-high strength steels.In this paper,rare earth La and Ce elements were added to Fe-Ni-Al system martensitic aging steel,and the metamorphic mechanism of non-metallic inclusions in steel with different rare earth elements was investigated by scanning electron microscopy,energy spectrometry(SEMEDS)and electron probe(EPMA)analyses combined with FactSage thermodynamic calculations.The results showed that the addition of rare earth elements to martensitic ageing steel resulted in the formation of rare earth-containing RE-O-S and RE-Al-O,which inhibited the formation of Al_(2)S_(3) and had no significant effect on the formation of AlN inclusions,and the shape of the inclusions was transformed from a strip-like and irregular geometry to a near-spherical shape after the modification of the inclusions by rare earths.Thermodynamic calculations showed that after the addition of rare earth elements,the thermodynamic stability of inclusions in the steel might be formed roughly as REAlO_(3)→Al_(2)O_(3)→rare earth sulfides→AlN.After the addition of rare earths,the RE_(2)O_(3) and Al_(2)O_(3) had been stable in the high-temperature molten state of the liquid steel,and with the lowering of the cooling temperature inclusions formed in the order of REAlO_(3)→RE_(2)O_(2)S→RES,and the inclusions of rare-earth La and Ce showed basically the same evolutionary path.

关 键 词：马氏体时效钢 稀土元素 夹杂物变质 热力学计算 

分 类 号：TF76[冶金工程—钢铁冶金] TG142[一般工业技术—材料科学与工程]