厚规格镀铝锌产品锌花尺寸及均匀性控制研究  

Research on spangle size and uniformity control of the thick gauge galvalume products

作　　者：徐呈亮 滕华湘 刘新华[2] 郭海涛[2] 李文通 黄旭[2] XU Chengliang;TENG Huaxiang;LIU Xinhua;GUO Haitao;LI Wentong;HUANG Xu(Shougang Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing,100043,China;Shougang Jingtang United Iron and Steel Co.,Ltd.,Tangshan 063200,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]首钢京唐钢铁联合有限责任公司,河北唐山063200

出　　处：《轧钢》2022年第4期61-69,共9页Steel Rolling

基　　金：河北省重点研发计划项目(20311004D)。

摘　　要：针对1.5 mm以上厚规格镀铝锌DX51D+AZ产品易出现边部锌花不均、锌花尺寸偏大等问题,采用扫描电镜(SEM)、辉光分析(GDS)、三维形貌测试等方法对厚规格镀铝锌DX51D产品锌花不均缺陷机理和锌花尺寸控制理论进行了系统分析,发现造成产品边部锌花不均缺陷的主要原因是基板表面粗糙度不均,通过炉辊更换、原料板形优化、炉辊变频器改造等措施,显著降低了该缺陷的发生率。结合热力学计算,发现锌花尺寸偏大的主要原因是镀后冷却能力不足,并探讨了微量Ti可以通过促进TiAl_(3)相形成从而起到细化凝固组织的作用。因此,提出了采用小锌花专用冷却装置并对原有移动风箱进行整体改造,以及添加微量Ti的措施,经过现场试制,锌花尺寸由2.9~3.0 mm减小至2.5~2.6 mm。采用上述措施后,锌花尺寸及均匀性控制水平得到显著提升。Aiming at the problems of non-uniformity of edge spangles and the large spangle size of the galvalume DX51 D+AZ products with the thickness of more than 1.5 mm, scanning electron microscopy(SEM), glow discharge emission spectrometry(GDS) and 3 D surface topography test were used to systematically analyze the non-uniformity defect mechanism of spangle and spangle size control theory of thick gauge galvalume DX51 D products. It is found that the main reason for the non-uniformity defects of the spangle on the edge of the products should be the non-uniform surface roughness of the substrate. And the occurrence rate of this defect was significantly reduced by tackling key measurements such as the replacement of furnace rollers, the optimization of the raw strip shape and the modification of the frequency converter of the furnace rollers. Combined with the thermodynamic calculations, it is found that the main cause of the large spangle size turns out to be insufficient cooling capacity after the galvanizing process. It was also discussed that a trace amount of Ti could play a role in refining the solidified microstructure by promoting the formation of TiAl_(3)phase. Therefore, the measurements of adopting a special cooling device, carrying out overall reconstruction of the original mobile air box and adding trace amounts of Ti were proposed for small spangles. After on-site trial production, the spangle size was reduced from 2.9-3.0 mm to 2.5-2.6 mm.The spangle size and uniformity control level were significantly improved after using above measures.

关 键 词：热浸镀 铝锌镀层 锌花不均缺陷 锌花尺寸控制 基板表面粗糙度 镀后冷却 微量Ti 

分 类 号：TG174.4[金属学及工艺—金属表面处理]