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以稀土镁球墨铸铁为研究对象,用扫描电镜观察了其中的夹杂物,并进行元素面扫描分析,结合热力学计算结果和动力学条件,分析了Ti-Ce-S复合夹杂物的形成过程。结果表明,Ti-Ce-S复合夹杂物呈块状,分布在珠光体和铁素体的晶界处,尺寸为3μm;球化处理过程中,CeS为TiS的形成提供非均匀形核核心,Ce对TiS的还原作用是促进Ti-Ce-S复合夹杂物形成的主要因素,Ti-Ce还与镧、钡、镁等元素复合形成夹杂物,分别是Ti-Ce-La-S、Ti-Ce-Ba-S、Ti-Ce-Ba-Si-S、Ti-Ce-V-C和Ti-Ce-La-Mg-C-N-S复合夹杂物。钛、铈等元素间的充分反应和此类夹杂物的有效去除是保证球化效果的重要因素。
The rare earth magnesium nodular cast iron was taken as the research object. The inclusions were observed by scanning electron microscopy. The elemental surface scanning analysis was carried out. The formation process of Ti-Ce-S composite inclusions was analyzed by thermodynamic calculation and kinetic conditions. The results show that the Ti-Ce-S composite inclusions are massive and distribute in the grain boundaries of pearlite and ferrite with a size of 3μm. During the spheroidization process, CeS provides a heterogeneous nucleation nucleus for the formation of TiS, The reduction of Ce to TiS is the main factor to promote the formation of Ti-Ce-S composite inclusions. Ti-Ce also forms inclusions with lanthanum, barium and magnesium, which are Ti-Ce-La-S and Ti- Ce-Ba-S, Ti-Ce-Ba-Si-S, Ti-Ce-VC and Ti-Ce-La-Mg-CNS composite inclusions. Titanium, cerium and other elements between the full response and the effective removal of such inclusions is an important factor to ensure the ball effect.