摘要
20#钢穿舱件和锡青铜阀电偶腐蚀是船舶海水管路系统严重腐蚀部位之一。为控制20#钢/锡青铜电偶腐蚀延长海水管路系统寿命,本文通过原位测量20#钢管材和ZCuSn5Pb5Zn5锡青铜管材在静态以及1、3和5 m/s流速海水中的电偶电位和电偶电流,分析电偶腐蚀速率随时间和流速的变化规律;同时采用扫描电镜(SEM)和激光Raman光谱仪分析腐蚀形貌和腐蚀产物组分。结果表明,在不同流速海水中,20#钢与ZCuSn5Pb5Zn5合金间存在明显的电偶腐蚀倾向,20#钢作为阳极加剧腐蚀,ZCuSn5Pb5Zn5合金作为阴极受到保护;相比于静态海水,20#钢阳极极化电流密度和ZCuSn5Pb5Zn5合金阴极极化电流密度在流动海水中显著增加,电偶腐蚀显著加剧,1 m/s流速下的电偶腐蚀速率是静态下的17.5倍;当海水流速达到5 m/s后,20#钢表面形成了致密性较高、活性低的腐蚀产物沉积层,电偶腐蚀速率减小。
The galvanic corrosion of the couples of 20#steel penetrating cabin parts and tin bronze valve is the severely corroded parts in the sea water pipeline system of ships.In order to control the galvanic corrosion of the couple 20#steel/tin bronze to extend the life of the seawater pipeline system,the galvanic potential and galvanic current of the couple 20#steel pipe/tin bronze pipe in static and flowing sea water of 1,3,and 5 m/s were assessed in-situ,respectively.Whilst,the variations of galvanic corrosion rate with time and flow rate were acquired;At the same time,scanning electron microscope(SEM)and laser Raman spectrometer were used to analyze the corrosion morphology and the composition of corrosion products.The results show that there is an obvious galvanic corrosion tendency between 20#steel and ZCuSn5Pb5Zn5 in seawater of different flow rates,namely 20#steel acts as the anode,and presents intensified corrosion tendency,while ZCuSn5Pb5Zn5 acts as the cathode.The anodic polarization current density of 20#steel and the cathodic polarization current density of ZCuSn5Pb5Zn5 increase significantly in flowing seawater rather than in static seawater,therewith the galvanic corrosion is signifi-cantly intensified.The galvanic couple in flowing seawater of 1 m/s presents a corrosion rate 17.5 times higher than that in static seawater.When the seawater flow rate reaches 5 m/s,a corrosion product scale with higher compactness and low activity is formed on the surface of 20#steel,and the galvanic corrosion rate decreases.
作者
刘近增
邢少华
钱峣
张大磊
马力
LIU Jinzeng;XING Shaohua;QIAN Yao;ZHANG Dalei;MA Li(State Key Laboratory for Marine Corrosion and Protection,Luoyang Ship Material Research Institute,Qingdao 266237,China;School of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China)
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2023年第1期127-134,共8页
Journal of Chinese Society For Corrosion and Protection
关键词
电偶腐蚀
流动海水
20#钢
锡青铜
原位测量
galvanic corrosion
flowing sea water
20#steel
tin bronze
in-situ measurement
