Corrosion: Oil leaking radiator

Dionne, Jean-François
5/30/2023 9:34 AM

High power electric transformers need forced cooling to work properly. Such is the case with electric high speed trains. One client was faced with cooling fluid leaking out the radiators of many of its trains. Investigative work was done on a leaking part to find the root cause of the failure.

The radiator is made of aluminium and protected with a conversion coating. The coating was appropriately selected for the train’s expected environment: saline coastal travel in Mediterranean climate. Yet corrosion still occurred.

The chemical signal obtained from the corrosion products showed high concentrations of sodium but lacked the chlorine signal expected from a seaside environment. After deeper investigation and discussion with the maintenance team, it was discovered that the cleaning detergent contained high amounts of sodium. Furthermore, the detergent’s pH was highly alkaline and aluminium alloys are prone to corrosion in such solutions. A very unexpected root cause!

#corrosion #root-cause #asset #integrity