(1. 華南理工大學(xué) 材料科學(xué)與工程學(xué)院，廣州 510640；
2. 鞍海鍍鋅設(shè)備有限公司，鞍山 114225)
摘 要: 利用掃描電鏡(SEM)、能譜分析(EDS)、腐蝕質(zhì)量損失試驗等手段分別研究工業(yè)鋅鍋焊接接頭焊縫區(qū)、熱影響區(qū)(HAZ)和母材區(qū)的顯微組織及其在450 ℃鐵飽和鋅液中長期浸泡后的腐蝕行為。結(jié)果表明：焊接接頭組織極不均勻；相同浸鋅時間下，腐蝕速率呈以下規(guī)律：vweld＞vHAZ＞vparent。且隨著浸鋅時間的延長，不同區(qū)域腐蝕速度差異逐漸變小。浸鋅1 h后，焊縫區(qū)的金屬間化合物主要由厚而粗大破碎的ζ相組成，而熱影響區(qū)的則有大量顆粒狀ζ相；浸鋅24 h后，3種基體的化合物層組織形貌相似，均由厚而致密的δ相層和薄的ζ相層組成。根據(jù)基體成分及金屬間化合物生長情況可知：短時間浸鋅時，焊縫中的硅含量是導(dǎo)致其腐蝕速率高的主要原因。
關(guān)鍵字: 鋅鍋；焊縫；腐蝕；熔融鋅液；熱鍍鋅
（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
