【摘要】 本文用籽晶插入热分析法研究了RE_3.78Si_51.0Fe_24.92Mg_12.0Al_6.6Ca_1.7多元球化剂在铁水中的冶金行为。背射成分象,X射线微区成分和X射线物相分析等表明,上述球化剂是一个复杂的多相合金,其中除纯元素外,还有SiO₂、SiMg₂、CaO、FeSi₂、CeO₂、CaCe等化合物以及其它更复杂的多元化合物。当球化剂以一定尺度的质点进入铁水后,其温度迅速上升,当达到1100℃时,在质点中开始发生一系列放热的物化反应,构成一个个微型的冶金单元。铝的作用是释放镁、铈、硅等球化、孕育元素。稀土、镁、硅、钙等以质点为中心逐渐向四周扩散,而形成“元素富集区”、“过渡区”和“球化区”。随时间的推移,“富集区”和“过渡区”逐渐消失。更多还原

【Abstract】 In this paper the metallurgical behaviour of rare earth nodulizer containing RE_3.78Si_51.0Fe_24.82Mg-（12.0）Al_6.6Ca_1.7 in molten iron is studied by means of seed crystal insertion thermal analysis. From the back reflection composition image, X-ray microanalysis and SEM, it shows that this nodulizer is an extremely complex multi-composition alloy. Besides the pure elements there are SiO₂, SiMg₂, CaO, FeSi₂, CeO₂, CaCe and other complex compounds. Metallographic investigation shows that the seed crystal does not dissolved completely. That part close to the seed crystal is the region rich in nodulizer, next is the transition region, which is wrapped by a spheroidal graphite regiorn, and then are the normal and bottom region in sequence. In the transition region a lot of exploded and chunky graphite exists. The spheroidal graphite in the third region is typically spheroidal with radiation under polarized light. Obvious boundaries are present between transition region and region containing spheroidal graphite. When the nodulizer particles drop into the molten iron they are heated by the currounding metal, the temperature raise up rapidly to 1100℃ and a series of physico-chemical reaction happen. In such a way a micro-metallurgical unitis formed.更多还原