(1. 华南理工大学 材料科学与工程学院，广州 510640；
2. 鞍海镀锌设备有限公司，鞍山 114225)
摘 要: 利用扫描电镜(SEM)、能谱分析(EDS)、腐蚀质量损失试验等手段分别研究工业锌锅焊接接头焊缝区、热影响区(HAZ)和母材区的显微组织及其在450 ℃铁饱和锌液中长期浸泡后的腐蚀行为。结果表明：焊接接头组织极不均匀；相同浸锌时间下，腐蚀速率呈以下规律：vweld＞vHAZ＞vparent。且随着浸锌时间的延长，不同区域腐蚀速度差异逐渐变小。浸锌1 h后，焊缝区的金属间化合物主要由厚而粗大破碎的ζ相组成，而热影响区的则有大量颗粒状ζ相；浸锌24 h后，3种基体的化合物层组织形貌相似，均由厚而致密的δ相层和薄的ζ相层组成。根据基体成分及金属间化合物生长情况可知：短时间浸锌时，焊缝中的硅含量是导致其腐蚀速率高的主要原因。
关键字: 锌锅；焊缝；腐蚀；熔融锌液；热镀锌
（1. College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. Anhai Galvanizing Equipment Company, Anshan 114225, China）
Abstract:The microstructure and corrosion behavior of weld metal, hot affected zone (HAZ) and parent metal of the zinc kettle weld joint dipped in saturated iron molten zinc at 450 ℃ were studied by scanning electron microscope (SEM), energy diffractive spectrum (EDS) and corrosion mass loss experiment. The results show that the microstructure of weld joint is very nonuniform. The corrosion rates of the three areas for same immersion time are in the following rule: vweld＞vHAZ＞vparent. With increasing the immersion time, the corrosion rates of different zones tend to be similar. After dipped in molten zinc for 1 h, the intermetallic compounds of coating of weld zone are mainly composed of thick and lumpy ζ grains, while a large number of granular ζ phase forms in HAZ. After dipped in molten zinc for 24 h, the three areas have similar coatings with thick and compact δ layer and thin ζ layer. According to the composition of weld joints and the growth situation intermetallic compounds of coating, the silicon content of weld metal is the main cause of the high corrosion rate for short immersion time.
Key words: zinc kettle; weld; corrosion; molten zinc; hot galvanizing
