Development of a New Pole Figure Method for Directly Projecting Crystal Grains with High Speed and High Resolution Using Synchrotron Radiation and Its Application to Observe Electrical Steel Sheets and Mild Steel Sheets at High Temperature

摘要

Taking advantage of the high brilliance of synchrotron radiation and the high sensitivity of an Imaging Plate, a new pole figure method was developed for projecting crystal grains directly with high speed and high resolution. This direct method replaced the replaced the traditional indirect point-by-point pole figure method, and an application field can be extended to dynamic and local area studies. Combining with a furnace for X-ray study, dynamic observation of secondary recrystallization process of electrical steel sheets was carried out at Photon Factory, National Laboratory for High Energy Physics, and explosive growing process of Goss-oriented grains was observed. Furthermore, Austenite pole figures of mild steel sheets were measured at high temperatures, revealing the formation mechanism of transformation texture. Also primary recrystallization process was studied: for example, changes in projected patterns of aluminum alloys during rolling and recrystallization.