非均质形核细化16Mn钢凝固组织

Refining the solidification structure of 16Mn steel by heterogeneous nucleation

通过感应炉对比实验,考察了基于不同非均质形核理论计算所得的三类有效形核质点Ce_2O_3、ZrO_2和MgO对细化16Mn钢凝固组织的影响.结果表明:只符合点阵错配度理论判据的MgO形核质点将铸锭等轴晶率从32%提高至37%;只符合静电作用理论判据的ZrO_2形核质点将等轴晶率提高至40%;同时满足点阵错配度理论和静电作用理论判据的Ce_2O_3非均质形核质点将等轴晶率提高至44%.在上述三个非均相成核的粒子中,Ce_2O_3能最大程度细化16Mn钢凝固组织.钢中形成以上三类形核核心后,钢的原始奥氏体晶粒尺寸以及显微组织均得到不同程度细化.

The influence of three effective nucleation particles of Ce2O3, ZrO2 and MgO based on calculations from different heterogeneous nucleation theories oil the refining solidification structure of 16Mn steel was studied by induction furnace contrast experiment. The equiaxed crystal ratio of ingots increases from 32%） to 37% by heterogeneous nucleation MgO particles which are only consistent with the criterion of the lattice disregistry theory; it increases to 40% by ZrO2 particles which only consist with the criterion of the electrostatic effect theory; and it increases to 44%, by Ce2O3 particles which follow the criteria of both the lattice disregistry theory and electrostatic effect theory. Among the above three heterogeneous nucleation particles, Ce2O3 has the maximum ability to refine the solidification structure of 16Mn steel. The prior austenite grain size and microstructure of 16Mn steel are refined in different degrees alter the at）ove three kinds of nucleation particles form in molten steel.