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可锻铸铁的石墨化机理迄今尚未弄明。利用电子探针分析有利于深化认识,去揭示石墨的本质。本文研究了常规成分下,铸态组织和高温石墨化组织中元素的分布规律,提出:(1)渗碳体内缺乏石墨化的内因与外因,它的分解需通过碳向奥氏体中溶解而实现;(2)硫化物和氧化铝在升温的前半期。对石墨化起重要作用;(3)原有的和新生的奥氏体-渗碳体晶界在升温的后半期,对石墨化起主导作用;(4)硅在升温的后期和保温阶段,显著地促进了石墨化。
The mechanism of graphitization of malleable iron has not been elucidated so far. The use of electronic probe analysis is conducive to deepening understanding, to reveal the essence of graphite. In this paper, the distribution regularities of elements in as-cast and high-temperature graphitized structures under conventional composition were studied. The main conclusions are as follows: (1) The intrinsic and extrinsic factors of graphitization in cementite are not enough, its decomposition needs to be dissolved by carbon into austenite Achieve; (2) sulfide and alumina in the first half of warming. Plays an important role in the graphitization; (3) the original and newborn austenite-cementite grain boundaries play a leading role in the graphitization in the latter half of the heating; (4) Graphitization is significantly promoted.