The main factors causing metal rust: relative humidity of the atmosphere at the same temperature, the percentage of water vapor content and water vapor saturation content in the atmosphere, known as relative humidity. Under certain relative humidity, the corrosion rate of metal antirust oil is very small, but higher than the relative humidity, the corrosion rate increases suddenly. This relative humidity is called the critical humidity. When the humidity in the atmosphere is higher than the critical humidity, the metal surface will appear water film or water droplets, if the atmosphere contains harmful impurities, dissolved in the water film, water droplets, electrolytes and aggravate corrosion.
