Hot-Model Experimental Study on Change Mechanism of Compactness Degree of Central Equiaxed Grains in Continuous-Casting Billets
Over the years,many works have been done about the defect formation and the methods for controlling equiaxed grains ratio in order to improve the internal quality,but there are few investigations about the related solidification-structure compactness degree of central equiaxed grains.The authors ever performed a special study about the compactness degree of central equiaxed grains based on the numerical modeling,and it is found that the compactness degree of central equiaxed grain zone in the billet is closely related to the centre solidification time (i.e.,it decreases with the increase of the centre solidification time).However,the previous study was only based on numerical modeling.Consequently,Confocal Laser Scanning Microscope (CLSM) is used to conduct hot-model experiments in this paper,and change mechanism of compactness degree of central equiaxed grains is investigated based on the influences of cooling rate in different stages and superheat on the compactness degree.Firstly,cooling rate of solidifying stage is found to have a great influence on the compactness degree,which is consistent with the previous result by using numerical modeling.Secondly,cooling rate of eliminating superheat also has an influence on the compactness degree.Moreover,it is shown that,at to the compactness degree,the influence abilities of cooling rates in different stages are different.From strong to weak,the order of the ability is cooling rate of earlier solidifying stage,cooling rate of eliminating superheat stage and cooling rate of later solidifying stage.Finally,under some certain conditions,the influencing ability of cooling rate on compactness degree is stronger than that of the superheat.
continuous casting billet equiaxed grains compactness degree cooling rate hot-model experiment
Zibing HOU Han CHEN Xinzhong HE Wei WANG Guanghua WEN Ping TANG
College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China Hunan Valin Lianyuan Iron&Steel Co.,Ltd,Hunan Valin Steel Co.,Ltd,Loudi 417009,China
国际会议
the 6th International Congress on the Science and Technology of Steelmaking,ICS2015(第六届国际炼钢科技大会)
北京
英文
452-456
2015-05-12（万方平台首次上网日期，不代表论文的发表时间）