铸轧铝合金带坯横纹缺陷产生原因分析及其控制  

Cause analysis and control of transverse defect in twin-roll casting aluminum alloy strip

作　　者：张开宝 张宏强 李斌亮 丁万武[2] ZHANG Kaibao;ZHANG Hongqiang;LI Binliang;DING Wanwu(Gansu Dongxing Jiayu New Material Co.,Ltd.,Jiayuguan 735100,Gansu,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]甘肃东兴嘉宇新材料有限公司,甘肃嘉峪关735100 [2]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《有色金属科学与工程》2023年第6期843-849,共7页Nonferrous Metals Science and Engineering

基　　金：嘉峪关科技计划资助项目(21-10);甘肃省重点研发计划工业领域项目(20YF3GB027)。

摘　　要：采用铜辊套双辊连续铸轧生产3系铝合金,通过分析铸轧板材横纹缺陷暗纹和亮纹的枝晶组织特点,以及铸轧过程中结晶前沿的动态变化特点,研究了铸轧生产过程中板面出现横纹缺陷的原因,并提出了控制措施。结果表明:凝固壳与轧辊表面反复接触和脱离造成轧辊对熔体的冷却不连续,从而导致带坯表层结晶的不连续,最终形成了板面横纹缺陷,而光亮晶的形成加剧了横纹缺陷的严重程度。当铸轧速度提高到一定值时,轧辊向凝固壳的靠近速度(V_(a))大于或等于凝固壳的收缩速度(Vs),初始凝固壳与轧辊表面之间不产生气隙,同时抑制光亮晶的形成,可以显著减轻甚至消除铸轧板横纹缺陷。3xxx series aluminum alloys were produced by continuous casting and rolling with copper roll sleeves.By analyzing the characteristics of the dendrite structure with dark and bright striations in cast-rolled plates,and the dynamic changes of the crystallization front in the process of casting and rolling,the reasons for the occurrence of these striations on the plate surface during such process were studied,with control measures proposed.The results showed that the repeated contact and separation between the solidified shell and the roll surface caused discontinuous cooling of the melt by the roll.This led to the discontinuous crystallization on the surface layer of the strip billet,and finally formed the transverse defect on it.The formation of bright crystals even aggravated the severity of the transverse defect.When the casting rolling speed increased to a certain value,the approaching speed(V_(a))of the roll towards the solidified shell was greater than or equal to its shrinkage speed(Vs).There was no air gap between the initial solidified shell and the roll surface.At the same time,the formation of bright crystals was restrained,which could significantly reduce or even eliminate the transverse defect of the casting plates.

关 键 词：铜辊套铸轧 横纹缺陷 凝固壳 嘴辊间隙 弯液面 光亮晶粒 铸轧速度 

分 类 号：TG335.13[金属学及工艺—金属压力加工] TG339