【作者】 王伟； 侯自兵； 陈晗； 邓刚； 文光华； 唐萍；

【Author】 Wang Wei;Hou Zibing;Chen Han;Deng Gang;Weng Guanghua;Tang Ping;College of Materials Science and Engineering,Chongqing University;

【机构】 重庆大学材料科学与工程学院冶金工程系；

【摘要】 共聚焦激光扫描显微镜高温系统(Confocal laser scanning microscope high temperature system,CLSM-HT)广泛用于研究金属凝固过程中相变、第二相析出行为及钢液中夹杂物的聚集等现象,但对共聚焦激光扫描显微镜高温系统下实验钢样凝固组织研究很少。为了扩展共聚焦激光扫描显微镜高温系统在热态模拟方面的应用,就很有必要研究试验钢样凝固组织的形貌特征。因此,本文以70号钢为试验钢种,研究该CLSM-HT不同凝固阶段冷却速度下试样凝固组织的形貌特征。研究发现试样整个观察面凝固组织分布不均匀,内部与外部凝固组织存在差异,同时存在柱状晶与等轴晶;对比同一试样的外部区域和内部区域,发现外部二次枝晶间距的小于内部二次枝晶间距(外部为内部之比范围为0.837~0.946),且两区域的差异程度随凝固阶段冷却速度的增大而增大。更多还原

【Abstract】 Confocal laser scanning microscope high temperature system, which is abbreviated as CLSM-HT, is widely used for study of the phase transition during solidification process, the behavior of the second phase precipitation and inclusion gathered in molten steel and the like. However, the solidified structure morphology of experimental steel samples using CLSM-HT has not been studied specially now. Then, it is very necessary to study the solidified structure morphology of experimental steel samples to extend the application of CLSM-HT for hot-model experiment. Therefore, high carbon steel(0.70% C) as test material, the study about solidified morphology of different cross section under different solidifying cooling rate(5 ~ 25℃ / min) is carried out. It is found that the solidified morpholog distribution of the specimen is not uniform in the whole viewing surface, presence of columnar crystals and the equiaxial crystals at the same time, and there is a difference between the central area of the specimen and the outer region on its solidification structure. Then, the same same observation surface is divided into two parts: the outer region and the inner region. Outer secondary dendrite arm spacing is less than the inner secondary dendrite arm spacing(the ratio of outer region to inner region is 0.837 ~ 0.946). And the different extent between two regions is increased with the increase of cooling rate during solidification stages更多还原