Growth kinetics and morphology of grain boundary ferrite allotriomorphs in an Fe-C-V alloy
Growth kinetics and morphology of grain boundary ferrite allotriomorphs in an Fe-C-V alloy
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Fe-C-V 合金中晶界铁素体同素异形体的生长动力学和形貌
DOI：
10.1007/bf02814226
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
G. Shiflet
中科院分区：
文献类型：
--
作者：
T. Abe;H. Aaronson;G. Shiflet
Fe-0.12%C-0.11%V合金在800 ℃ ~ 870 ℃温度范围内发生反应时，晶界铁素体的同素异形体形成两种形态：长径比约为一半的常规同素异形体和长径比接近于零的“蛇形”。界面钒碳化物（VC）沉淀密集，与常规的他晶型有关，但不与“蛇晶”有关。增稠动力学的“蛇”是约一个数量级慢于预测的准平衡模型。另一方面，传统的同素异形体与由准平衡预测的动力学一致。这些观察结果被认为是溶质拖曳效应和“在V存在下铁素体对奥氏体晶界的润湿性”。在845 ° C附近，界面碳化物沉淀的近似上限温度，常规同素异形体的增厚动力学没有明显变化，这强烈支持这样的观点，即这种碳化物只能沉淀在不动的，即，奥氏体的部分共格区域：铁素体边界。
Grain boundary ferrite allotriomorphs in an Fe-0.12 pct C-0.11 pct V alloy reacted in the temperature range 800‡ to 870 ‡C develop in two morphologies: conventional allotriomorphs, with an aspect ratio of about one-half, and “snakes≓, whose aspect ratio approaches zero. Interphase boundary vanadium carbides (VC) precipitate densely in association with conventional allotriomorphs but not with “snakes≓. Thickening kinetics of “snakes≓ are about an order of magnitude slower than predicted by the paraequilibrium model. Conventional allotriomorphs, on the other hand, thicken with the kinetics predicted by paraequilibrium. These observations are considered in terms of the solute drag-like effect and of “wetting≓ of austenite grain boundaries by ferrite in the presence of V. Absence of a distinct change in the thickening kinetics of conventional allotriomorphs in the vicinity of 845 ‡C, the approximate upper temperature limit of interphase boundary carbide precipitation, strongly supports the view that such carbides can precipitate only on immobile,i.e., partially coherent areas of austenite : ferrite boundaries.