Si含量与表面缺陷对Q235热轧钢板热镀锌层的影响规律  

Effect of Si content and surface defects on hot-dip galvanizing layer of Q235 hot-rolled steel sheet

作　　者：牛跃威 李逸伦 刘超 杨志刚 黄伟丽 杨树峰[4] NIU Yue-wei;LI Yi-lun;LIU Chao;YANG Zhi-gang;HUANGWei-li;YANG Shu-feng(Technology Center,Delong Steel Co.,Ltd.,Xingtai 054009,Hebei,China;Hebei Hot Rolled Plate and Strip Technology Innovation Center,Xingtai 054009,Hebei,China;Institute for Advanced Materials and Technology,University of Science and Technology,Beijing 100083,China;School of Metallurgical and Ecological Engineering,University of Science and Technology,Beijing 100083,China)

机构地区：[1]德龙钢铁有限公司技术中心,河北邢台054009 [2]河北省热轧板带钢技术创新中心,河北邢台054009 [3]北京科技大学新材料技术研究院,北京100083 [4]北京科技大学冶金生态与工程学院,北京100083

出　　处：《中国冶金》2023年第3期85-93,共9页China Metallurgy

基　　金：国家自然科学基金资助项目(52104319)。

摘　　要：为研究Si含量及表面缺陷对Q235热轧钢板表面热镀锌层的影响规律,使用涂层测厚仪、扫描电镜和能谱等研究了不同Si含量及不同表面理化性质的Q235热轧钢板在相同浸镀条件下的热镀锌试样截面形貌、厚度和元素分布。结果表明,Si元素质量分数大于0.15%时,钢材表面镀层中出现因Al元素偏聚而导致的Zn-Al相减少和纯Zn相分布集中,界面处形成了异常生长的Fe-Al金属间化合物,导致镀层厚度增加和结合力下降;火焰切割侧钢的镀层中发现了由孔洞造成的Fe-Al金属间化合物层缺失,导致了镀层向内拓展和镀层厚度不均匀。因此,用于热镀锌的Q235钢Si元素质量分数应控制在0.15%以下,并减少使用火焰切割工艺,或对火焰切割板进行表面处理以提高钢板表面镀层的质量。In order to study the effect of Si content and surface defects on hot-dip galvanizing layer of Q235 hot-rolled steel sheet, the cross-sectional morphology, thickness and element distribution for hot-rolled steel sheets of Q235 with different Si content and different surface physicochemical properties under the same dip coating conditions were investigated using coating thickness gauge, scanning electron microscopy and energy spectroscopy and so on. The results show that, when the mass fraction of Si element is greater than 0.15%, the Zn-Al phase decreases and the pure Zn phase concentrates due to the bias of Al elements, and abnormal Fe-Al intermetallic compounds grows at the interface, leading to increase in the thickness and decrease in the bonding strength of the layer. The absence of Fe-Al intermetallic compound layer due to holes in the plating for flame-cut side of the steel is found, leading to inward expansion of the layer and uneven layer thickness. Therefore, the mass fraction of Si element in Q235 steel used for hot-dip galvanizing should be controlled below 0.15%, and the use of flame cutting process can be reduced, or the surface treatment of the flame-cut plate can be carried out to improve the quality of the steel surface plating.

关 键 词：热镀锌 SI含量 热轧钢板 Q235 热加工 火焰切割 

分 类 号：TG174.4[金属学及工艺—金属表面处理]