海洋大气环境中Q420qENH耐候钢腐蚀演化及力学性能研究  

Study on the Corrosion Evolution and Mechanical Properties of Q420qENH Weathering Steel in Marine Atmospheric Conditions

作　　者：程海根[1,2] 邹鹏 郑尚敏[1] 龚汉隆 吴天文 CHENG Haigen;ZOU Peng;ZHENG Shangmin;GONG Hanlong;WU Tianwen(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China;State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学土木建筑学院,江西南昌330013 [2]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,江西南昌330013

出　　处：《材料保护》2025年第4期131-141,共11页Materials Protection

基　　金：国家自然科学基金会项目(51968024)。

摘　　要：随着近年来耐候钢在桥梁领域的不断发展,耐候钢免涂装使用案例屡见不鲜,但耐候钢适用的服役环境有待考究,尤其是在腐蚀性较强的海洋性大气等复杂环境中服役时。为此,以藏木雅鲁藏布江特大桥用钢Q420qENH为研究对象,通过电解加速腐蚀试验模拟海洋大气腐蚀环境,探究Q420qENH在此类腐蚀环境中的腐蚀行为、耐候钢母材及其对接接头经过腐蚀后的力学性能削减程度。基于腐蚀动力学、锈层形貌演化、物相组成、电解腐蚀试验的加速效果、力学性能削减程度进行多角度综合分析。结果表明:Q420qENH在海洋大气腐蚀环境中的腐蚀速率先增后减。Q420qENH耐候钢主要依靠Fe_(3)O_(4)形成较为厚实且略为致密的锈层以阻碍大气环境中的水、氧气、污染物对基体的直接侵蚀。但表面锈层形貌疏松多孔,阻止腐蚀介质侵入的效果有限,并且Q420qENH在海洋大气腐蚀环境中难以形成致密表面锈层,腐蚀等级介于C3~C4之间,因此,认为Q420qENH并不适合在海洋大气腐蚀环境中免涂装使用。在力学性能方面,耐候钢母材及其对接接头腐蚀4、8、14 h后,屈服强度、抗拉强度和延伸率较未腐蚀时削减程度逐渐上升,但电解加速腐蚀14 h后其屈服强度均在360 MPa以上,抗拉强度均在466 MPa以上,腐蚀后的力学强度仍处于较高水平。With the continuous development of weathering steel in the field of bridges in recent years,there have been numerous cases of weath-ering steel being used without coating,but the service environment for weathering steel needs to be studied,especially in the complex environ-ment such as highly corrosive marine atmosphere.Therefore,taking Q420qENH steel used in the Zangmu Yarlung Zangbo River extra-large bridge as the research object,the marine atmospheric corrosion environment was simulated using an electrolytic accelerated corrosion test.The corrosion behavior of Q420qENH in this environment and the reduction in the mechanical properties of the weathering steel base metal and its butt joint after corrosion were investigated.Based on the corrosion kinetics,morphology evolution of the rust layer,phase composition,the ac-celeration effect of the electrolytic corrosion test,and the reduction in mechanical properties,a multi-angle comprehensive analysis was con-ducted.Results showed that the corrosion rate of Q420qENH in the marine atmosphere increased initially and then decreased.The weathering steel primarily relied on Fe_(3)O_(4) to form a thick,slightly dense rust layer,which prevented direct erosion of the substrate by water,oxygen and 132 pollutants in the atmospheric environment.However,the surface rust layer was loose and porous,limiting its ability to prevent the invasion of corrosive media.Additionally,it was difficult for Q420qENH to form a dense surface rust layer in the marine atmospheric corrosion environ-ment.The corrosion grade was between C3 and C4,and it was concluded that Q420qENH was unsuitable for coating-free use in such environ-ments.In terms of mechanical properties,the degrees of reduction in yield strength,tensile strength and elongation of the base metal of the weathering steel and its butt joint after 4,8 and 14 h of corrosion gradually increased compared to those without corrosion.However,after 14 h of accelerated corrosion,the yield strength and tensile strength remained above 360 MPa and

关 键 词：耐候钢 Q420qENH 海洋大气腐蚀 锈层形貌 力学性能 

分 类 号：TG172[金属学及工艺—金属表面处理]