大气腐蚀下耐候钢的初期行为规律

 研究了耐候钢在40 ℃ 和100%RH高温高湿环境中初期大气腐蚀行为规律。结果表明，耐候钢初期大气腐蚀行为符合幂函数规律，随着Cu含量的增加，代表腐蚀发展趋势的n值减小，说明Cu有助于减缓耐候钢的腐蚀发展趋势。通过SEM扫描电镜和显微激光拉曼光谱分析模拟大气腐蚀初期腐蚀产物的形成和发展得知，在大气腐蚀初期，腐蚀产物形貌为团状和链状，团状腐蚀产物主要由γ Fe2O3和γ FeOOH构成，而链状腐蚀产物为α FeOOH。

Atmospheric Corrosion Behavior of Weathering Steels in Initial Stage

The behavior of the initial stage of atmospheric corrosion for weathering steels at 40 ℃ and 100%RH was investigated. The kinetics of atmospheric corrosion was found to obey Exponential law. The n values of weathering steels decrease when the content of Cu increases. The Cu helps to decrease corrosion rate of wheathering steel. The formation and development of corrosion products on weathering steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM) and Raman spectroscopy. The results showed that two different shapes of corrosion products, ie cluster and chain like particles, were formed in the initial stage of corrosion. The cluster products were composed of lepidocrocite (γ FeOOH) and maghemite (γ Fe2O3) transformed from lepidocrocite. The chain like particle products were goethite(α FeOOH). A formation mechanism of the corrosion products is proposed.