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
田方铖 1高雪云 2曹悦 1邢磊 2华连庚 3王海燕2
作者信息
- 1. 内蒙古科技大学材料与冶金学院,内蒙古 包头 014010
- 2. 内蒙古科技大学材料与冶金学院,内蒙古 包头 014010;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
- 折叠
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Al2S3 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REAlO3→Al2O3→稀土硫化物→AlN.加入稀土后,在高温熔融态下钢液中RE2O3 和Al2O3 就已稳定存在,并且随着冷却温度的降低,钢中的夹杂物按REAlO3→RE2O2S→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.
Abstract
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 differ-ent rare earth elements was investigated by scanning electron microscopy,energy spectrometry(SEM-EDS)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 forma-tion of rare earth-containing RE-O-S and RE-Al-O,which inhibited the formation of Al2S3 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 inclu-sions 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 REAlO3→Al2O3→rare earth sulfides→AlN.After the addition of rare earths,the RE2O3 and Al2O3 had been stable in the high-temperature molten state of the liquid steel,and with the lowering of the cooling temperature inclu-sions formed in the order of REAlO3 → RE2O2S → 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Key words
martensitic steels/rare earth element/inclusions modification/thermodynamic calculation引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据