取向硅钢中高斯晶粒异常长大选择性行为

Selective abnormal growth behavior of Goss grains in a grain-oriented silicon steel

对CGO取向硅钢二次再结晶中断实验进行了研究,发现二次再结晶升温过程中,仅在异常长大开始前,高斯晶粒尺寸明显大于其他晶粒,且不同取向晶粒的数量与脱碳退火时的特征一致.高斯晶粒晶界上MnS等抑制剂的优先粗化使高斯晶粒能够率先发生异常长大,且只有晶界弯曲严重或经过很小的生长几个晶粒就能合并的高斯晶粒才能成为二次晶核.在高斯晶粒异常长大过程中,晶界形貌参差不齐,呈岛屿状.研究表明:高斯晶粒独特的生长方式,可能是使二次再结晶能很快完成的原因.

Experiments were performed by interrupting secondary recrystallization processes in a CGO silicon steel.The results show that the average size of Goss grains is obviously larger than that of other grains just before abnormal growth in the temperature-rising process of secondary recrystallization.The amount of different orientation grains at this stage is almost the same as that in a decarburizing-annealed sample.Goss grains can first grow abnormally due to preferred coarsening of such inhibitors as MnS in Goss grains.It is noted that only Goss grains with seriously curved grain boundaries or several grains merged by slight growth can be the nuclei of secondary grains.During abnormal growth of Goss grains,their grain boundaries have zigzag shapes.It is believed that this unique growth pattern is the reason that secondary recrystallization can finish quickly.