摘要
应用氧氮分析、扫描电镜夹杂物自动分析、热力学计算等方法,研究了Al含量不同的三种典型汽车用高强钢中夹杂物的数量、种类、析出温度的变化规律.结果表明,钢中Al的质量分数从0. 054%增加到1. 35%,钢中的T[O]质量分数从0. 00150%减少到0. 00075%,夹杂物数量从38. 28 mm-2减少到28. 12 mm-2,钢中夹杂物的数量呈减少趋势.随着钢中Al的质量分数的增加,钢中氧化物夹杂的演变规律为Al_2O_3·MnO→MgAl_2O_4,铝系夹杂物的演变规律为Al_2O_3→AlN,硫化物夹杂的演变规律为MnS→MgS.热力学计算表明,AlN夹杂的生成与钢中的Al含量有关,Al含量高的钢中AlN夹杂更易生成; AlN的析出温度随着Al含量的增加而上升,析出温度分别为1375、1528和1561 K.
With the addition of Al,the type,amount and precipitation temperature of inclusions in high strength steel for automobile will change. The characteristics of inclusions including amount,species and precipitation temperature in three typical automotive high strength steels with different Al contents were investigated by oxygen and nitrogen analysis,scanning electron microscopy ( SEM) , and thermodynamic calculation. The results show that the mass fraction of Al in steel increases from 0. 054% to 1. 35%,the mass fraction of T[O]in steel decreases from 0. 00150% to 0. 00075%,and the number of inclusions decreases from 38. 28 mm-2 to 28. 12 mm-2 ,the number of inclusions in steel tends to decrease. With the increase of Al mass fraction in the steel,the evolution route of main oxide inclusions is Al2O3·MnO→MgAl2O4 ,the main aluminum inclusion changes from Al2O3 to AlN;and the evolution route of sulfide inclusions is MnS to MgS. The thermodynamic calculations indicate that the formation of AlN inclusions is related to the Al content in the steel,and the AlN inclusions in steel with high Al content are easier to be formed. The precipitation temperature of AlN increases with the increase of Al content,and the precipitation temperatures are 1375,1528 and 1561 K,respectively.
作者
肖超
崔衡
XIAO Chao;CUI Heng(Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China;Institute of Engineering Technology,University of Science and Technology Beijing,Beijing 100083,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2018年第S1期26-30,共5页
Chinese Journal of Engineering
关键词
高强钢
铝含量
夹杂物
氮化铝
热力学计算
high strength steels
aluminum content
inclusions
aluminum nitride
thermodynamic calculation
作者简介
通信作者:崔衡,E-mail:cuiheng@ustb.edu.cn.
