建筑护栏用热挤压Mg-6.5Al合金在雨水中的耐腐蚀性能分析  

Analysis of the Corrosion Resistance of Hot Extrusion Mg-6.5Al Alloy for Building Guardrails in Rain Water

作　　者：王智博[1] 朱俊涛[2] 邓鹏鹏 WANG Zhi-bo;ZHU Jun-tao;DENG Peng-peng(Department of Architectural Engineering,Henan Vocational and Technical College of Communications,Zhengzhou 450046,China;School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China;College of Civil and Hydraulic Engineering,Xichang University,Xichang 615013,China)

机构地区：[1]河南交通职业技术学院建筑工程系,河南郑州450046 [2]郑州大学土木工程学院,河南郑州450001 [3]西昌学院土木与水利工程学院,四川西昌615013

出　　处：《材料保护》2020年第10期30-32,33,50,共5页Materials Protection

基　　金：河南省高等学校重点科研项目(20B570006)资助。

摘　　要：为了提高建筑护栏用Mg-6.5Al合金在雨水中的耐腐蚀性能,采用260℃热挤压比20∶1处理以提高Mg-6.5Al合金的综合性能。通过扫描电镜、X射线衍射仪、电化学工作站研究了镁合金经过热挤压处理前后其显微组织结构以及腐蚀性能的变化。结果表明:热挤压处理并未改变合金物相结构,在α-Mg基体上存在β-Al以及部分MgAl相。经过热挤压处理后,MgAl组织获得了更均匀的分布形态。随着时间的增加,热挤压后的合金试样表现出更低的析氢速率,获得了更强的耐蚀能力。对热挤压态合金进行腐蚀处理后其表面更加光滑,形成了部分腐蚀坑,但腐蚀坑数量降低。热挤压态合金经腐蚀测试表明形成了Mg(OH)2与MgO产物,经热挤压处理的合金形成具有致密结构的腐蚀膜组织。In order to improve the corrosion resistance of Mg-6.5Al alloy for building guardrail in rain water,the comprehensive performance of Mg-6.5Al alloy was improved by using hot extrusion at 260 ℃ with a ratio of 20∶1. The microstructure and corrosion behavior of magnesium alloy before and after hot extrusion were studied by means of scanning electron microscope,X-ray diffraction and electrochemical workstation.Results showed that the phase structure of the alloy was not changed by the hot extrusion treatment,and it was the α-Mg substrate with someβ-Al as well as MgAl phases. After the hot extrusion treatment,the MgAl phase obtained a more uniform distribution. With the increase of time,the hot extrusion sample showed a faster rate of hydrogen evolution than the as-cast one and gained the stronger corrosion resistance.Moreover,the corrosion treatment of the hot-extruded alloy resulted in a smoother surface,and some corrosion pits formed,the number of which was reduced compared with that of the as-cast alloy. It was showed that the Mg(OH)2 and MgO products formed by analysis of corrosion test on the hot extruded alloy,and the generated corrosion film structure possessed a dense structure.

关 键 词：镁合金 热挤压 电化学测试 腐蚀行为 雨水 

分 类 号：TG146.2[一般工业技术—材料科学与工程]