高强度海工钢中腐蚀活性夹杂物与耐海水腐蚀性能研究

摘要：利用金相显微镜（OM）和扫描电子显微镜（SEM）观察和分析不同厚度（12和355mm）的EH36钢板中腐蚀活性夹杂物的形貌和尺寸分布；使用X射线能谱仪（EDS）分析腐蚀活性夹杂物的成分；采用电化学腐蚀和室内模拟海水加速腐蚀实验分析EH36钢板的耐腐蚀性能。结果表明：活性夹杂物主要成分为Al、Mg复合氧化物，组成主要为MgO·Al2O3。钢板的饱和电流密度、腐蚀失重速率和腐蚀活性夹杂物密度存在正相关性。即腐蚀活性夹杂物密度低，则饱和电流密度低，腐蚀失重速率也低；反之亦然，腐蚀活性夹杂物密度高，则饱和电流密度高，腐蚀失重速率也高，海工钢中存在的腐蚀活性夹杂物是引发腐蚀的根源。

Study on corrosion active inclusions and seawater corrosion resistance of high strength marine steel

The morphology and size distribution of corrosive active inclusions in EH36 steel plate with different thicknesses (12 and 35.5mm) were observed and analyzed using the optical microscope (OM) and scanning electron microscope (SEM). The composition of corrosion active inclusions was researched by energy dispersive X-ray spectrometer (EDS). The electrochemical corrosion test and accelerated corrosion test in simulated seawater were conducted to explore the corrosion resistance of EH36 steel plate. The results show that the main composition of active inclusions is composite oxides of Al and Mg with the main composition of MgO·Al2O3. There is a positive correlation between saturation current density, corrosion weight loss rate and corrosion active inclusion density. That is, when the density of corrosion active inclusions is low, the saturation current density and the corrosion weight loss rate are low; vice versa, when the corrosion active inclusion density is high, both the saturation current density and the corrosion weight loss rate are high. This is because the corrosion active inclusions are the reasons for the corrosion initiation and propagation in EH36 steel plates.