桥梁钢Q345q在3种模拟大气环境中的腐蚀行为研究  

Corrosion Behavior of Q345q Bridge Steel in Three Simulated Atmospheres

作　　者：郭铁明[1] 张延文 秦俊山 宋志涛 董建军 杨新龙 南雪丽[1] GUO Tieming;ZHANG Yanwen;QIN Junshan;SONG Zhitao;DONG Jianjun;YANG Xinlong;NAN Xueli(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;Gansu Jiu Steel Group Hongxing Iron & Steel Co., Ltd., Jiayuguan 735100, China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]甘肃酒泉集团宏兴钢铁股份有限公司,嘉峪关735100

出　　处：《中国腐蚀与防护学报》2019年第4期319-330,共12页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51461029);广东省“扬帆计划”引进创新创业团队专项资助(2015YT02G090);甘肃省交通厅科研项目(2017-16和2017-19)~~

摘　　要：选择3种模拟西北地区大气环境的腐蚀介质(除冰盐介质、工业大气介质及除冰盐+工业大气介质),采用干湿交替加速腐蚀实验研究了桥梁钢Q345q的腐蚀行为,通过失重法探讨了桥梁钢Q345q在3种不同腐蚀环境下的腐蚀动力学曲线,并采用XRD、SEM和电化学工作站等分析了桥梁钢Q345q腐蚀不同时间形成的锈层物相、形貌、结构及其电化学特性。结果表明:虽然在除冰盐介质中480 h内腐蚀速率小,但表面形成含有β-FeOOH和氯化物等不稳定可溶性的腐蚀产物,导致锈层疏松,腐蚀电流增大,锈层不具保护性;在NaHSO3介质中的腐蚀速率较高,但随着腐蚀时间的延长锈层致密性增加,腐蚀速率下降较快,锈层阳极稳态腐蚀电流减小,锈层具有保护性;而在混合介质中腐蚀行为为耦合效应,由于氯化物等腐蚀产物使得锈层致密性下降,但锈层仍具有一定的保护性。Corrosion behavior of Q345 q bridge steel was studied by dry-wet alternating accelerated corrosion test method with three designed media, which aim to simulate three environmental conditions commonly encountered in the Northwest China, namely deicing-, industrial-and industrial with deicingconditions respectively. While the corrosion kinetics curves of Q345 q bridge steel were measured by weight loss method. The morphology, microstructure and phase composition, as well as the electrochemical properties of the rust scales of Q345 q bridge steel corroded for different time were assessed by means of SEM, XRD and electrochemical workstation. Results show that although the corrosion rate is small in the deicing salt medium within 480 h, the corrosion product contains unstable and soluble compounds such as β-FeOOH and chloride, which results in loose rust scale, the corrosion current of the rust scale increases with time, thus which is poor in protectiveness. The corrosion rate in the sodium bisulfite medium is higher, but with the increase of corrosion time, the corrosion rate decreases rapidly, the anode corrosion current of the rust scale decreases, therewith, the rust scale is protective. In the mixed medium,the corrosion behavior is a coupling effect. Due to the existence of corrosion products such as chlorides,the compactness of the rust scale is poor, but which exhibits protectiveness to a certain degree in comparison with that in the deicing salt medium.

关 键 词：桥梁钢Q345q 除冰盐 NaHSO3介质 混合介质 腐蚀行为 

分 类 号：TG172.3[金属学及工艺—金属表面处理]