Fe－C合金高温保温过程中碳化物表面形貌连续变化的研究  

STUDY OF THE CONTINUOUS MORPHOLOGICAL CHANGES OF CARBDE DURING HIGH TEMPERATURE HOLDINO OF Fe-C ALLOYS

作　　者：马前[1] 柳百成[1] 王兆昌[1] 

机构地区：[1]清华大学,北京科技大学

出　　处：《钢铁》1994年第5期45-49,34,共6页Iron and Steel

摘　　要：研究了白口铸铁高温保温过程中同一共晶碳化物颗粒的形貌变化过程，结果表明，在保温过程中，共晶碳化物表面会形成一些小的孔洞，继续保温时，这些孔洞（包括原有的孔洞）会进一步扩展、连接，最终使碳化物分割并进而发生粒状化。理论分析与实验结果证明，与单纯由表面自由能的降低所引起的形貌变化不同，由碳化物的体积分数减少所必然导致的碳化物表面形貌的变化，不取决于碳化物表面的曲率状况。因而只要碳化物发生明显的溶解（体积分数减少），在大的板块状碳化物上就总有可能会形成孔洞。孔洞的形成和扩展是使碳化物断网的机制之一。AbstractAn investigation was made of the morphological changes of the same eutectic carbide parti-cle in white cast irons during high temperature holding treatment.It was clearly observed that during the holding small holes appeared on the surface of the eutectic carbide, and then the holes(including the original holes)expanded and connected as the holding time increased. As a result the eutectic carbide broke up and granulated.Unlike the case of capillarity induced morpholo-gical changes,theoretical analyses and experimental results demonstrated that the morphological changes of carbide caused by the reduction of its volume fraction did not depend upon the cur-vatures of the carbide at the interface.Thus small holes could always form on the surface of large plate-like carbid so long as the carbide dissolved obviously,i.e.,the volume fraction of the carbide reduced largely.Formation and expansion of holes is one of the mechanisms of the breakup of carbide network.

关 键 词：白口铁 高温保温 碳化物 形貌变化 

分 类 号：TG143.1[一般工业技术—材料科学与工程]