【摘要】 研究了海洋工程用国产D36、F460和F690钢的显微组织,以及在20,50℃模拟海水(质量分数3.5%NaCl溶液)中的电化学腐蚀行为。结果表明:热机控制工艺轧制D36钢的显微组织为铁素体、珠光体和少量魏氏组织,经淬火+回火热处理的F460和F690钢的显微组织均为细小板条贝氏体;在NaCl溶液中,D36、F460和F690钢的耐腐蚀性能和抗点蚀能力依次增大;与20℃下的相比,3种试验钢在50℃下的自腐蚀电流密度明显增大,耐腐蚀性能降低;在NaCl溶液中长时间浸泡后,D36、F460和F690钢的表面腐蚀产物膜厚度依次降低,腐蚀产物膜内元素种类依次增多,3种试验钢整体上均呈现均匀腐蚀特征。更多还原

【Abstract】 Microstructures and electrochemical corrosion behaviors in simulated seawater(3.5 wt% NaCl solution)at 20,50℃of domestic D36,F460 and F690 steels for marine engineering were studied.The results show that the microstructure of D36 steel rolled by thermo-mechanical control process consisted of ferrite,pearlite and a little widmanstatten structure.The microstructures of F460 and F690 steels after quenching and tempering treatment were both composed of fine bainite lath.In the NaCl solution,the corrosion resistance and pitting corrosion resistance of D36,F460 and F690 steels increased in turn.Compared with those at 20 ℃,the free corrosion current density at 50 ℃ of the three tested steels increased significantly,and the corrosion resistance decreased.After long-term immersion in the NaCl solution,the thicknesses of surface corrosion product film on D36,F460 and F690 steel decreased in turn,and the element type in the corrosion product film increased in turn.The three tested steels showed overall uniform corrosion characteristics.更多还原