海水介质下铜合金空冷器管失效原因分析

某型柴油机空气冷却器在服役过程中发现铜管腐蚀泄漏,铜管已经由内壁向外壁腐蚀穿孔。文中采用化学成分分析、金相分析、显微硬度测试、腐蚀表面形貌分析(SEM和EDS)等方法对空冷器管的腐蚀失效原因进行分析,结果表明:海水介质下,海洋生物在管内壁的沉积以及海水中腐蚀性氯离子、硫离子与铜基体引起微电池反应是空冷器管腐蚀穿孔的主要原因,并提出了相应的腐蚀控制建议。

Failure analysis of copper alloy tube of air cooler under the sea

A corrosion leak has been found on a copper alloy tube of air cooler on a diesel engine in service, which appears as a hole from inner wall to outer surface. This paper carries out the analysis of corrosion failure of the air cooler through chemical composition analysis, metallurgical analysis, microhardness test, and morphology analysis of the corrosion surface by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). It is indicated that the corrosion hole on the air cooler is mainly caused by the deposit of the marine creatures on the inner wall, and the microbattery reaction between copper matrix and corrosive chloride ion and sulphur ion in the sea. Several suggestions have been provided for the corresponding corrosion control.