某型船挠性接管法兰腐蚀原因分析

Corrosion Reason Analysis of Flange for Flexible Pipe of a Certain Type of Vessel

某型船海水管路挠性接管法兰出现腐蚀渗漏现象,为明确其腐蚀渗漏原因,对该法兰材料进行了化学成分分析和金相分析,对腐蚀区域进行了微观形貌观察和能谱分析。结果表明:渗漏法兰中锌含量超标,基体中大量的锌在海水条件下作为阳极优先溶解,剩下富铜基体,并在法兰密封表面形成连续的微型通道,海水不断向内部及周围渗入,最终贯通于整个密封面凸台,导致泄漏。

Corrosion and leakage phenomenon occurred on a flange for flexible pipe in seawater pipeline of a certain ship.In order to find the corrosion and leakage reasons,chemical composition analysis and metallographic examination were conducted on the flange material,micro-morphology observation and energy spectrum analysis were carried out on the corrosion area.The results show that the zinc content in the leaky flange exceeded the standard.A large amount of zinc in the matrix was preferentially dissolved as an anode under seawater conditions,leaving a copper-rich matrix and forming a continuous micro-channel on the flange sealing surface.Seawater continued to infiltrate into and around,and eventually penetrated the entire sealing surface boss,resulting leakage.