Customarily, metal buttons are called rust or rust due to corrosion or discoloration caused by oxygen, moisture and other polluting impurities in the atmosphere. After the metal products of plastic button manufacturers are rusted, the light ones will affect the appearance quality, and the serious ones will affect the use and even cause scrapping. Therefore, metal products must be properly kept during storage, and attention should be paid to anti-rust.Gold Brass Button
The main factors that cause metal buttons to rust:
(1) Atmospheric relative humidity At the same temperature, the percentage of the water vapor content of the atmosphere and its saturated water vapor content is called relative humidity. Below a certain relative humidity, the metal corrosion rate is very small, but above this relative humidity, the corrosion rate increases sharply. This relative humidity is called critical humidity. The critical humidity of many metals is between 50% and 80%, and that of steel is about 75%. Atmospheric relative humidity has the greatest influence on metal corrosion. When the atmospheric humidity is higher than the critical humidity, a water film or water droplets will appear on the metal surface. If the harmful impurities contained in the atmosphere dissolve in the water film or water droplets, it will become an electrolyte, which will aggravate the corrosion.Gold Brass Button
(2) Air temperature and humidity The relationship between atmospheric temperature and humidity affects the corrosion of metal buttons. This has the following main conditions: first, the water vapor content of the atmosphere increases with the increase of temperature; second, high temperature promotes the intensification of corrosion, especially in humid environments, the higher the temperature, the faster the corrosion rate. When the relative humidity is low, the effect of temperature on corrosion is not obvious, but when the relative humidity is higher than the critical humidity, the amount of corrosion increases sharply with the increase of temperature. In addition, if there is a temperature difference between the atmosphere and the metal, condensed water will form on the metal surface with low temperature, which will also cause the metal to rust.Gold Brass Button
(3) Corrosive gases pollute the corrosive gases in the air, and sulfur dioxide has the greatest impact on metal corrosion, especially on copper and its alloys. Sulfur dioxide in the atmosphere mainly comes from the combustion of coal. At the same time, the combustion product carbon dioxide also has a corrosive effect. Corrosive gases are mixed in the atmosphere around the plant. Such as hydrogen sulfide, ammonia gas, hydrochloric acid gas, etc. are all factors that promote metal corrosion.
(4) Other factors The atmosphere contains a lot of dust, such as smog, coal ash, chloride and other acid, alkali, salt particles, etc., some of which are corrosive in themselves, or condensation nuclei of water droplets, which are also corrosion factors. For example, chloride is considered to be the "mortal enemy" of corroding metals.Gold Brass Button
Post time: May-10-2023