石墨球长大机制的探讨

Study on Growth Mechanism of Spherical Graphite

通过热力学和动力学计算和分析得知 :在气泡学说中 ,石墨球长大方式主要是离心生长而不是向心生长 .在离心生长的同时碳原子通过扩散进入内腔并将其填满 .通过对石墨球最终表面的形态进行分析 ,可以获得气泡的表面并不是石墨球的最终表面 ,石墨球表面主要由于受到石墨球表面各微晶长大速度不均匀性、铁水中的三大起伏、微量元素与碳原子的竟相吸附、由于浓度梯度和温度梯度所引起铁水的对流等各种因素的综合影响结果使其表面成为凹凸起伏的形状 .

By thermodynamically and dynamically calculating and analysing ,a new growth mechanism of spherical graphite has been proposed ,that is,the spherical graphite does not grow inwardly,but grow outwardly and when spherical graphite grow outwardly carbon atoms come into and fill-up the entocoele of spherical graphite by the diffusing way.Through analysing to the superficial shape of the finial spherical graphite,it is proved that the superficial shape of the bubble is not the finial surface of spherical graphite .The wavy surface of the finial spherical graphite chiefly results from many respects such as:the inhomogeneity growing of all microcrystallite in the surface of spherical graphite、the three large rising and falling in the molten iron 、the race of adsorption between trace elements(or imperities)and carbon element、the convection current of molten iron caused from the gradient of temperature and density and so on.