ABSTRACT

The composition, morphology, number, area, size and average distance of inclusions in Fe–23Mn–xAl–0.7C steels were evaluated through an inclusion automatic analysis system (INCA Feature). According to their composition and morphology, six types of inclusions are classified in the present steels: MnS(Se), AlN, Al₂O₃, AlN–MnS(Se), Al₂O₃–MnS(Se), and other inclusions (i.e. Al₂O₃–AlN and MgO–Al₂O₃). Thermodynamic calculation results show that AlN inclusions are formed in molten steel with Al contents of 3.28 and 6.76 wt-%. Irregularly shaped MnS(Se) inclusions precipitate during the solidification processe. AlN and Al₂O₃ generally serve as sites for the heterogeneous nucleation of MnS(Se). Sometimes, AlN particles can precipitate on the surfaces of Al₂O₃ and MnS(Se) inclusions in the solidification process. As the Al content increases to 6.76 wt-%, a large number of agglomerated AlN and AlN–MnS(Se) inclusions are observed. Agglomerated AlN inclusions normally form in the smelting process due to the combined effects of the cavity bridge force and viscous resistance.

摘要

通过夹杂物自动分析系统（INCA Feature）对 Fe-23Mn- x Al-0.7C 钢中夹杂物的成分、形态、数量、面积、尺寸和平均距离进行评估。根据其成分和形态，现有钢中夹杂物可分为六类：MnS(Se)、AlN、Al ₂ O ₃、AlN-MnS(Se)、Al ₂ O ₃ -MnS(Se)和其他夹杂物（即 Al ₂ O ₃ -AlN 和 MgO-Al ₂ O ₃）。热力学计算结果表明，AlN 夹杂物在钢水中形成，Al 含量为 3.28 和 6.76 wt-%。不规则形状的 MnS(Se) 夹杂物在凝固过程中析出。AlN和Al ₂ O ₃通常用作MnS(Se)的异质成核位点。有时，AlN 颗粒会在凝固过程中沉淀在 Al ₂ O ₃和 MnS(Se) 夹杂物的表面。随着 Al 含量增加到 6.76 wt-%，观察到大量团聚的 AlN 和 AlN-MnS(Se) 夹杂物。由于腔桥力和粘性阻力的共同作用，在熔炼过程中通常会形成团聚的 AlN 夹杂物。