海洋大气环境下稀土及铌微合金钢的腐蚀行为研究  

Study on the Corrosion Behavior of Rare Earth/Niobium Microalloyed Steels in Marine Atmospheric Environments

作　　者：张弦 胡泓亦 龚丽 汪致远 彭鼎 祝长金 韦文追 吴开明 ZHANG Xian;HU Hong-yi;GONG Li;WANG Zhi-yuan;PENG Ding;ZHU Chang-jin;WEI Wen-zhui;WU Kai-ming(Collaborative Innovation Center for Advanced Steels,Wuhan 430081,China;Hubei Province Key Laboratory of Systems Science in Metallurgical Process,Wuhan 430081,China;Division of Applied physics,College of Science,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]高性能钢铁材料及其应用省部共建协同创新中心,湖北武汉430081 [2]冶金工业过程系统科学湖北省重点实验室,湖北武汉430081 [3]武汉科技大学理学院应用物理系,湖北武汉430081

出　　处：《材料保护》2021年第6期7-15,33,共10页Materials Protection

基　　金：国家级大学生创新创业训练计划项目(201810488035);国家自然科学基金青年基金项目(51601138,51601137);国家材料环境腐蚀平台项目(2014CB643300)资助。

摘　　要：为给微合金钢的设计开发理论提供数据支撑,通过显微组织表征、干湿交替循环试验、中性盐雾试验和电化学分析等测试手段研究了稀土微合金钢和铌微合金钢在海洋大气环境中的腐蚀行为,对比分析了其耐腐蚀性能。结果表明:微合金钢的显微组织由铁素体和珠光体组成,并且铌微合金化有助于细化晶粒并能阻碍珠光体组织的形成。在腐蚀初期锈层的主要成分为γ-Fe_(2)O_(3),γ-FeOOH,对于基体的保护性并不明显。随着暴露周期的延长,γ-FeOOH逐渐转化为α-FeOOH,提高了锈层对基体的保护作用,从而使腐蚀电流密度下降,提升了2种钢的耐腐蚀性能。经过较长周期腐蚀后,铌微合金钢中晶粒的细化有利于增加表面锈层的致密性,α-FeOOH的含量相对较高,从而减慢了腐蚀速率。因此,相对于稀土微合金钢,铌微合金钢显示出更好的耐大气腐蚀性能。For providing the data support to design and develop microalloyzed steels,the corrosion behavior of rare earth microalloyed steels and niobium microalloyed steels in marine atmospheric environments was investigated by the means of surface microstructure characterization,alternative wet/dry cycle test,neutral salt spray test and electrochemical measurements.Furthermore,the corrosion resistance of microalloyed steels was compared and analyzed.Results showed that the microstructure of microalloyed steels consisted of ferrite and pearlite,and niobium microalloying favored the refinements of the grains and hindered the formation of pearlite.The rust layer was composed of forγ-Fe_(2)O_(3) andγ-FeOOH,which had no obvious protective effect to the substrate.With prolonging exposure periods,γ-FeOOH gradually transformed toα-FeOOH,enhancing the protective effect to the substrate.The corrosion current density of rare earth/niobium microalloyed steels declined,and thus the corrosion resistance of those two kinds of steels were improved.After a long period of corrosion,the grain refinement of niobium microalloyed steel was beneficial to increase the densification of the surface rust layer and the content ofα-FeOOH was relatively high,then further the corrosion rate was reduced.Hence,compared with rare earth microalloyzed steel,the niobium microalloyed steels presented a better atmospheric corrosion resistance.

关 键 词：微合金钢 海洋大气环境 腐蚀行为 稀土 铌 

分 类 号：TG172.3[金属学及工艺—金属表面处理]