摘要
用 Fe-C 合金的规则间隙溶体模型在新的贝氏体转变模式的基础上对 Fe-C 合金贝氏体转变初期进行了热力学分析。新的模式中,贝氏体铁素体以非平衡但不完全过饱和的碳量经由切变机制形成,碳的再分配先于贝氏体铁素体的形成。结果表明,在完善奥氏体中形成一定尺寸的贫碳区,其引起的能量升高与马氏体相变的形核垒有相同的数量级;在借助于体系的内部缺陷以及非平衡体系结构驰豫的情况下是可以实现的过程;在贝氏体铁素体碳量为非平衡但不完全过饱和的情况下,贝氏体转变的驱动力足以推动切变相变。
A model of the bainite transformation in Fe—C alloy during the initial stageof transformation(without carbide precipitation)has been proposed in which carbon parti-tioning is prior to the bainite ferrite formation through martensitic-tpye shear.Athermodynamic analysis of the bainite transformation using Xie and Kang′s regularinterstitial solution treatment of Fe—C solid solution is given.The analysis suggests that thecarbon content of bainite ferrite during the initial stage of transformation be calculated byletting the energy changeΔG^(γ→B)take the minimum to carbon content at B_s temperature.
基金
国家自然科学基金
5860306
关键词
FE-C合金
贝氏体相变
热力学
合金
bainite transformation
thermodynamics
carbon partitioning
driving force
shear
