材料与冶金学报2026，Vol.25Issue(1)：12-19,8.DOI:10.14186/j.cnki.1671-6620.2026.01.002
稀土La对2.0 GPa超高强度钢中夹杂物和性能的影响
Influence of rare earth lanthanum addition on inclusions and mechanical properties of 2.0 GPa ultra-high strength steel
摘要
Abstract
The effects of adding different mass fractions of rare earth La on the inclusions,microstructure,and mechanical properties of 2.0 GPa ultra-high strength steel,which was smelted by a vacuum induction furnace,have been investigated by means of a metallographic microscope,scanning electron microscope,EBSD analysis,XRD diffraction,and tensile and impact tests.The results reveal that as the mass fraction of La increases from 0(no addition)to 0.003 2％and then further to 0.022％in the steel,inclusions evolve from MgO·Al2O3 to LaAlO3-La2O2S complex,and later to rare earth composite oxysulfides LaS-La2O2S.The volume fraction of retained austenite after aging is from 1.85％to 3.05％and then to 5.17％,with the improvement rates of 64.9％and 69.5％,respectively.The Charpy impact energy increases from 11.9 J to 14.1 J and then to 15.3 J,with the improvement rates of 18.5％and 8.5％,respectively.Rare earth La plays a key role in modifying and spheroidizing inclusions in the steel,and increases the volume fraction of retained austenite,leading to a significant increase in impact energy.However,when La is excessively added to a mass fraction of 0.022％,the yield strength of the steel decreases from 1.596 GPa to 1.476 GPa,with a decrease of 0.120 GPa.It is concluded that the optimal addition of rare earth La is 0.003 2％,in this case,contributing to a noticeable increase in the toughness of 2.0 GPa ultra-high strength steel.关键词
稀土La/超高强度钢/洁净度/夹杂物改性/强韧性Key words
rare earth lanthanum/ultra-high strength steel/cleanliness/inclusion modification/strength and toughness分类
矿业与冶金引用本文复制引用
张云飞,战东平,李吉航,姜周华..稀土La对2.0 GPa超高强度钢中夹杂物和性能的影响[J].材料与冶金学报,2026,25(1):12-19,8.基金项目
山西省吕梁市校地合作重点研发专项项目(2023XDHZ05) （2023XDHZ05）
黑龙江省揭榜挂帅科技攻关项目(2022ZXJ03A02). （2022ZXJ03A02）
