Effect of metal ions on corrosion behavior of component coating in high temperature and humidity environment

In high temperature and humidity environment, the most common failure mode is component coating corrosion. Conventional high-pressure cooking tests use deionized water as the steam source, and do not consider the influence of trace metal ions in the real environment. This paper aims to study the acceleration of the corrosion of various metal ions (Na
⁺
, Zn
²⁺
, K
⁺
) on component coating under high temperature and high humidity environment. In the high temperature and high humidity environment, the accelerated corrosion test of various metal ions on the coating of components was carried out. EDS spectroscopy, scanning electron microscopy, scanning acoustic microscope and other equipment were used to analyze the morphology, metal compound composition and corrosion mechanism of the coating before and after the test. The accelerated conversion factor (ASF) method was used to process the test data. The proportions of coating corrosion area after the test were calculated by machine vision software ImageJ. And the corrosion rate curve was calculated based on proportions of coating corrosion area. Tests have proved that metal ions can accelerate the corrosion rate of component coatings. Through the test data, the accelerated conversion factor of various metal ions relative to the ion-free environment on the coating corrosion of components is calculated. For Na
⁺
, Zn
²⁺
and K
⁺
, the average corrosion acceleration conversion factor is 20, 72 and 26, respectively. The results of this paper can be used to guide the rapid evaluation of the corrosion adaptability of component coating acceleration in high temperature and humidity environments.