【摘要】 研究了Fe-C-Si合金中Ce量及凝固速度对石墨晶体形态转变的影响,首次提出了在球团状石墨与过冷石墨的转变或者蠕虫状石墨与片状石墨的转变过程中,以变质元素的含量变化为主要影响因素,并且以Ce_D←→D=0.0296lgR+0.162（％）及Ce（V←→A）=-0.0353lgR+0.147（％）为各自的临界加入量值.在球团状石墨与蠕虫状石墨的转变过程中,凝固速度的变化占主导地位,且以Rs=55×10^-2.5Ce（μm/S）和Rv=32.4×10^-2.3Ce（μm/S）为获得完全球团状或蠕虫状石墨的临界值。蠕虫状石墨能与片状石墨间相互连续生长过渡,认为蠕虫状石墨为一定变质元素含量及凝固速度条件下石墨晶体特有的组织形态,无须球化衰退或石墨球破碎为其生长前提。更多还原

【Abstract】 An investigation was made of the influence of modifying element Ce and of solidification rate on the structural transformation of graphite in the Fe-C-Si alloy. It is proposed that during the transformation between spheroidal and overcooled graphite or between vermicular and flake ones, the modifying element Ce added may be the main effective factor, and the critical wt-% of Ce addition for each transformation may be expressed as Ce_（S-D）=-0.0296 1g R+0.162 and Ce_（V-A）=-0.0353 1g R+0.147 respectively. The solidification rate seems to be predominant while the transformation between spheroidal and vermicular graphite, and the critical rate in μm/s to complete the spheroidal or vermicular graphite transformation may be R_s=55×10^-2.5Ce or R_v=32.4×10^-2.3Ce respectively. It is confirmed that the structural transformation between vermicular and flake graphite may be carried out continuously during the growth of graphite crystals. The graphite of vermicular structure is a special one which is growing up under certain conditions of modifying element Ce and solidification rate with no need to decay the nodularization or to break the graphite nodules prior to its growth.更多还原