电工钢热压缩时动、静态再结晶组织及取向分析

Analysis of dynamic and static recrystallization microstructure and orientations in a hot-compressed electrical steel

采用热模拟方法及EBSD技术,研究Fe-3 wt%Si电工钢在不同温度下组织的动、静态再结晶及晶粒取向特征,特别是少量奥氏体对铁素体动、静态再结晶组织及取向的影响。结果表明,不同温度形变的组织主要分三类:形变长条铁素体、珠光体和等轴细小铁素体。长条形变铁素体内发生动态回复或连续式的动态再结晶,奥氏体周围的铁素体动态再结晶加速,部分以传统的不连续方式动态再结晶。铁素体、奥氏体都可发生静态再结晶。奥氏体的静态再结晶在1050℃以上明显,铁素体的静态再结晶随温度的升高逐渐进行,最显著的再结晶发生在1050℃。不同温度形变的样品,其形变晶粒取向主要以<111>和<100>为主,小等轴铁素体晶粒除与大形变铁素体取向相近外,出现了<110>取向及其它取向。

Static and dynamic recrystallization and grain orientations in a hot-compressed Fe-3 wt% Si electrical steels were studied at different temperatures using Gleeble simulator and EBSD technique,particularly focusing on the effect of small amount of austenite on ferritic microstructure and orientations.The results show that microstructure of the compressed steel,depending on deformation temperature,consisted of elongated and deformed ferrite,pearlite and fine equal-axed ferrite.The elongated ferrite experienced dynamic recovery or continuously dynamic recrystallization,and the ferrite around austenite underwent accelerated dynamic recrystallization even in a discontinuous style.Static recrystallization was observed in both ferrite and austenite,and was most prominent in austenite at 1050 ℃,whereas it became more significant in ferrite with increasing deformation temperature.Grain orientations are mainly 111 and 100 in samples compressed at various temperatures.Most orientations of fine equal-axed ferrite are similar to those of elongated ferrite,however orientation of 110 is also observed.