热基锌铝镁镀层钢切边初始腐蚀机理和保护性能研究

庞晟, 何鑫, 商婷, 刘超, 程学群

doi:10.16577/j.issn.1001-1560.2024.0123

材料保护 >

2024 , Vol. 57 >Issue 6: 29 - 35

DOI: https://doi.org/10.16577/j.issn.1001-1560.2024.0123

研究篇

热基锌铝镁镀层钢切边初始腐蚀机理和保护性能研究

展开

(1. 芜湖新兴铸管有限责任公司, 安徽芜湖 241002;2. 北京科技大学 a. 新材料技术研究院, b. 国家材料腐蚀与防护科学数据中心, 北京 100083;3. 首钢集团有限公司技术研究院绿色可循环钢铁流程北京市重点实验室, 北京 100043)

刘超(1988-),博士，副教授，研究方向为微观组织结构诱发局部腐蚀机理研究与耐蚀钢研发，E-mail:liuchaoustb@163.com

收稿日期: 2024-01-26

修回日期: 2024-02-27

录用日期: 2024-03-20

网络出版日期: 2024-06-24

基金资助

国家自然科学基金项目(52104319)

收起

Initial Corrosion Mechanism and Protection Performance of Hot-Based Zn-Al-Mg Alloy Coating Steel Cut Edge

Expand

(1. Wuhu Xinxing Casting Pipe Co., Ltd., Wuhu 241002, China;2a. Institute of Advanced Materials & Technology, 2b. National Materials Corrosion and Protection Data Center,University of Science and Technology Beijing, Beijing 100083, China; 3. Technology Research Institute, Shougang Group Co., Ltd.,Beijing Key Laboratory of Green Recyclable Process for Iron & Steel Production Technology, Beijing 100043, China)

LIU Chao(1988-),Ph.D.,Associate Professor, Research Focus: Development of Corrosion Resistant Steel and Mechanism Research of Corrosion Resistant, E-mail: liuchaoustb@163.com

Received date: 2024-01-26

Revised date: 2024-02-27

Accepted date: 2024-03-20

Online published: 2024-06-24

Supported by

The National Natural Science Foundation of China (52104319)

Fold

摘要

以低铝低镁型Zn1.5Al1.1Mg热基锌铝镁镀层板为研究对象，采用SEM、EDS、XRD等方式，明确了低铝低镁锌铝镁镀层板其切边的初始腐蚀机制，并通过SEM、XRD对浸泡实验和循环腐蚀实验后的试样其切边处的腐蚀产物种类和形貌进行分析，研究锌铝镁镀层对其切边处的保护性能。结果表明：锌铝镁镀层其切边是由纯Zn相、Zn-MgZn₂二元共晶、Zn-MgZn₂-Al三元共晶3种组织构成；含有MgZn₂相的三元共晶和二元共晶在锌铝镁切边的腐蚀初期通常作为腐蚀萌生点，进而扩展到整个镀层；在锌铝镁镀层切边的长期腐蚀过程中，Zn元素起到主要保护作用，游离的Zn²⁺通过形成碱式碳酸锌[Zn₅(OH)₆(CO₃)₂]和碱式氯化锌[Zn₅(OH)₈Cl₂·H₂O]在镀层切边处堆积，阻碍腐蚀介质的纵向扩展，当其转变为多孔氧化锌时，镀层保护失效，切边受到破坏。

关键词： 热基锌铝镁镀层; 切边; 腐蚀机理; 微观组织; 循环腐蚀试验

本文引用格式

庞晟, 何鑫, 商婷, 刘超, 程学群 . 热基锌铝镁镀层钢切边初始腐蚀机理和保护性能研究[J]. 材料保护, 2024 , 57(6) : 29 -35 . DOI: 10.16577/j.issn.1001-1560.2024.0123

Abstract

The low-aluminum and low-magnesium Zn1.5Al1.1Mg hot-based Zn-Al-Mg alloy coated plate was employed as research object, the initial corrosion mechanism of the cut edges of low aluminum, low magnesium Zn-Al-Mg alloy coated plates was clarified by SEM, EDS, XRD and other methods. Moreover, through SEM and XRD method, the types and morphology of corrosion products at the cut edges of the specimens after immersion and cyclic corrosion experiments were analyzed for evaluating the protective performance of Zn-Al-Mg alloy coatings on their cut edges. Results showed that the cut edge of the Zn-Al-Mg alloy coating was composed of three microstructures: pure Zn phase, Zn-MgZn₂ binary eutectic and Zn-MgZn₂-Al ternary eutectic. In general, the ternary eutectic and binary eutectic containing MgZn₂ phase served as corrosion initiation points during the initial corrosion stage of Zn-Al-Mg alloy cut edges, and then extended to the entire coating. During the long-term corrosion process of cutting edges in Zn-Al-Mg alloy coatings, the Zn element played a major protective role. Specifically, free Zn²⁺ accumulated at the cutting edge of the coating by forming basic zinc carbonate [Zn₅(OH)₆(CO₃)₂] and basic zinc chloride [Zn₅(OH)₈C_l2·H₂O], hindering the longitudinal expansion of the corrosive medium. Nevertheless, when these precipitates transformed into porous ZnO, the protective capabilities of the coating failed, and the cut edge was damaged.

Key words： hot-based Zn-Al-Mg alloy coating; cut edge; corrosion mechanism; microstructure; cyclic corrosion test

Options

文章导航

模态框（Modal）标题

摘要

本文引用格式

Abstract