冷却速度对Al-Zn-Si-Mg镀层组织和耐蚀性能的影响  

EFFECT OF COOLING RATE ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Al-Zn-Si-Mg COATINGS

作　　者：于程福 梅淑文 宋志岗 张鹏 张杰[3] 韩世绪[1] 王海龙 Yu Chengfu;Mei Shuwen;Song Zhigang;Zhang Peng;Zhang Jie;Han Shixu;Wang Hailong(HBIS Group Tangsteel Company,Tangshan 063016,Hebei;Material Technology Research Institute of HBIS Group,Shijiazhuang 050023,Hebei;National Engineering Laboratory of Advanced Metal Material Coating,Iron and Steel Research Institute,Beijing 100081)

机构地区：[1]河钢集团唐钢公司,河北唐山063016 [2]河钢材料技术研究院,河北石家庄050023 [3]钢铁研究总院先进金属材料涂镀国家工程实验室,北京100081

出　　处：《河北冶金》2023年第1期39-44,共6页Hebei Metallurgy

摘　　要：采用扫描电镜(SEM)、能谱仪(EDS)、电化学试验、中性盐雾试验研究了10℃/s、15℃/s、25℃/s 3种冷却速度对Al-Zn-Si-Mg镀层组织及耐蚀性能的影响。结果表明:Al-Zn-Si-Mg镀层组织由富铝树枝晶(α-Al)、Al-Zn-MgZn2三元共晶相和富Si相组成;冷却速度由10℃/s提高至15℃/s时,Al-Zn-Si-Mg镀层的二次枝晶间距由21μm减少至12μm,共晶组织比例由21%提升至27%,中性盐雾出现红锈时间由4536 h延长到4872 h,耐蚀性提高;冷却速度由15℃/s提高至25℃/s时,Al-Zn-Si-Mg镀层的二次枝晶间距反而增大至15μm,且共晶组织比例减少至25%,中性盐雾出现红锈时间减少为3864 h,耐蚀性下降。综合分析后认为:镀后冷却速度15℃/s的Al-Zn-Si-Mg镀层组织细小均匀,耐蚀性最好。The effects of cooling rates at 10℃/s,15℃/s and 25℃/s on the microstructure and corrosion resistance of Al-Zn-Si-Mg coatings were investigated by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),electrochemical tests and neutral salt spray tests.The results show that the microstructure of Al-Zn-Si-Mg coating is composed of aluminum-rich dendrite(α-Al),Al-Zn-MgZn2 ternary eutectic phase and Si-rich phase.When the cooling rate increased from 10℃/s to 15℃/s,the secondary dendrite spacing of Al-Zn-Si-Mg coatings decreased from 21μm to 12μm,the eutectic structure ratio increased from 21%to 27%,the time of red rust of neutral salt spray increased from 4536 h to 4872 h,and the corrosion resistance was improved.When the cooling rate increased from 15℃/s to 25℃/s,the secondary dendrite spacing of Al-Zn-Si-Mg coatings increased to 15μm,the eutectic structure ratio decreased to 25%,the red rust time of neutral salt spray decreased to 3864 h,and the corrosion resistance decreased.After comprehensive analysis,it is concluded that Al-Zn-Si-Mg coating with cooling rate of 15℃/s after plating has fine and uniform microstructure and the best corrosion resistance.

关 键 词：Al-Zn-Si-Mg镀层 冷却速度 组织 耐蚀性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]