Effect of transformation temperature and C content on the crystailographic feature of upper bainite

摘要

[Introduction] In upper bainite structure, a prior gamma grain is divided into packets, the group of bainitic ferrite (BF) laths with the same habit plane, and each packet is further subdivided into blocks. Such morphological features are very similar to those of lath martensite. Recently, the crystailographic feature of lath martensite in Fe-C alloys with various carbon contents was studied extensively. However, there have been few studies on the crystailographic feature of upper bainite for various carbon contents. The purpose of this study is to investigate the effect of transformation temperature and carbon content on upper bainite structure in Fe-Ni-C alloys, especially focussing on the crystailographic feature of BF.