论文部分内容阅读
通过扫描电镜EBSD技术与光学显微镜分析了不同形变量的热轧板材在不同的纵断面上显微组织与小角度晶界数量的变化,研究了板材热轧与退火时的不均匀行为。研究表明:当热轧形变量为84%时,MGH754合金板材纵截面上心部晶粒尺寸大于边部,而小角度晶界比例相反。当热轧变形量为90%时,板材边部局部出现二次再结晶,形成混晶组织,导致心部与边部小角度晶界比例接近。1335℃高温退火后,板材边部均未发生二次再结晶,而心部均发生。小角度晶界比例越大,合金越不易发生二次再结晶。
The changes of microstructure and small-angle grain boundaries on different longitudinal sections of hot-rolled sheets with different deformations were analyzed by scanning electron microscopy (EBSD) and optical microscopy. The non-uniform behavior of hot-rolled and annealed sheets was studied. The results show that when the deformation of hot rolling is 84%, the grain size of the central part of the MGH754 alloy is larger than that of the edge, while the small angle grain boundaries are opposite. When the deformation amount of hot rolling is 90%, the secondary recrystallization appears locally on the edge of the sheet, forming the mixed crystal structure, resulting in the close ratio of the small angle grain boundaries between the heart and the edge. After annealed at 1335 ℃, secondary recrystallization did not occur on the edge of the plate, but the heart occurred. The larger the proportion of small-angle grain boundaries, the harder the alloy is to undergo secondary recrystallization.