Surface pretreatment method of antirust object:
1) Surface cleaning: bearing proper cleaning methods must be selected according to the properties of the surface to be rusted and the current Bearing Rust conditions. Solvent cleaning, chemical treatment cleaning and mechanical cleaning are commonly used.
2) After the surface is dry and cleaned, it can be dried with filtered dry compressed air, or dried with a Bearing Rust dryer at 120 ~ 170 ℃, or wiped with clean gauze.
Method of applying antirust oil
1) Immersion method: some small items are immersed in antirust grease and a layer of antirust grease is Bearing Rust adhered to their surface. The oil film thickness can be achieved by controlling the temperature or viscosity of antirust grease.
2) The brushing method is used for outdoor construction equipment or products with special shapes that are not suitable for soaking or spraying. Bearing Rust During brushing, attention should be paid not only to avoid accumulation, but also to prevent missing coating.
3) spray method can not be used to soak some large antirust substances by immersion method. Generally, the Bearing Rust filter compressed air of about 0.7Mpa pressure is used for spraying in the clean air area.
Spray method is suitable for solvent dilution antirust oil or thin layer Bearing Rust antirust oil, but must adopt perfect fire protection and labor protection measures.
Metal corrosion is caused by various internal and external factors. It can be summarized as follows: ① chemical composition and structure of metal Bearing Rust materials; ② Metal surface finish (oxygen concentration difference, battery corrosion);
③ Solution composition and pH value in contact with metal surface; ④ Bearing Rust Ambient temperature and humidity; ⑤ Various environmental media in contact with metal surface.
Why does hand sweat cause metal corrosion?
Human sweat is a colorless, transparent or light yellow liquid with salty taste and weak acid. Its pH value is 5 ~ 6. In addition to sodium, potassium, calcium and magnesium salts, it also contains a small amount of urea, lactic acid, citric acid and other organic acids.
When sweat comes into contact with metal, a layer of sweat film will be formed on the metal surface, which will cause electrochemical effect on the metal and corrode the metal.
Human sweating is inevitable. To prevent corrosion caused by hand sweat, production personnel should wear gloves, finger covers, or take parts with special tools. Do not touch the product casually.
There are cases where the grease changes color in the bearing. Even if it is not placed in the bearing, it will change color. This is because:
First, the grease has oxidation problems. When the grease is placed (or operated) for a period of time, it will have a lot of contact with oxygen. At the same time, the metal (bearing itself) acts as a catalyst in this oxidation reaction.
Therefore, oxidation should also be considered when calculating the replenishment time interval of grease in bearings. Many greases now have antioxidant additives. This does not mean that it will not oxidize.
Second, the temperature (bearing itself, or the environment) of the bearing itself will change, which will lead to the continuous flow of the base oil in the grease in and out of the thickener. At the same time, each time the base oil goes back, it may not go back completely.
After a long time, the performance of the grease will change and can not meet the lubrication, so it is necessary to apply lubrication again. The color of grease with insufficient base oil may change.
In addition, if the temperature is abnormal, the performance of the oil will change greatly. In this way, there will be discoloration. If the temperature is very high, it will carbonize. The color will darken.