The workpiece is rusted and the metal is corroded. How to use the anti-rust oil in the rainy season?
September 12, 2022
In the rainy season every year, the air humidity is high, the temperature is high, the clothes are prone to mold, and the workpieces in the factory are also prone to rust. If the metal workpiece cannot be properly rusted, it will cause rust. In order to avoid rust and reduce losses, protecting the workpiece with anti-rust oil is one of the most common protection methods at present. What are the main factors affecting metal corrosion?
Metal corrosion is caused by various internal and external factors, which can be summarized as follows: ①The chemical composition and structure of the metal material itself; ② Metal surface finish (battery corrosion due to oxygen concentration difference); ③The composition and pH value of the solution in contact with the metal surface; ④ Ambient temperature and humidity; ⑤ Various environmental media in contact with metal surfaces. Metal parts are often prone to rust during processing or storage, especially in wet seasons with high temperature and rain. After the workpiece is processed, if it cannot be delivered in a short time, the workpiece should be coated with anti-rust oil and packaged. The packaging steps can be referred to: first clean the surface of the workpiece with organic solvents such as detergent or alcohol, and then apply the anti-rust oil to the surface of the workpiece after about 2 hours. In order to improve the rust prevention effect of important parts such as the inner ring and cone surface of the bearing, it is necessary to seal them with wax. Two points should be paid attention to in the packaging process: one is not to wash with water or acidic solvent, and then wipe it with a clean gauze; the other is to apply anti-rust oil to cover all the workpieces.
Antirust pretreatment method on workpiece surface: 1) Surface cleaning: The cleaning method must be selected according to the nature of the workpiece surface and the conditions at that time. Commonly used are solvent cleaning method, chemical treatment cleaning method and mechanical cleaning method. If it is not cleaned or not cleaned properly, there may be hand sweat, dust and other residues on the metal surface, and there is a hidden danger of rust. Human sweat is a colorless, transparent or slightly yellowish, slightly acidic liquid with a salty taste, and its pH value is 5 to 6. In addition to sodium, potassium, calcium, and magnesium salts, it also contains a small amount of organic acids such as urea, lactic acid, and citric acid. When sweat comes into contact with metal, a sweat film will be formed on the surface of the metal, and the sweat film will cause electrochemical action on the metal and corrode the metal. It is inevitable for people to sweat. To prevent hand sweat from causing rust, production personnel should wear gloves, finger cots, or use special tools to pick up parts, and do not touch the product with hands. 2) After the surface is dry and cleaned, it can be dried with filtered dry compressed air, or dried with a dryer at 120~170 ℃, or dried with a clean gauze.
How to apply anti-rust oil: 1) Immersion method: Some small items are immersed in anti-rust grease, and a layer of anti-rust grease is adhered to the surface. Oil film thickness can be achieved by controlling the temperature or viscosity of the anti-rust grease. 2) Brushing method: It is used for outdoor construction equipment or special-shaped products that are not suitable for immersion or spraying. When brushing, attention should be paid not only to avoid accumulation, but also to prevent leakage. 3) Spray method: Some large rust preventives cannot be oiled by immersion method. The spray method is suitable for solvent-diluted rust preventive oil or thin-layer rust preventive oil, but perfect fire prevention and labor protection measures must be adopted.
When using anti-rust oil, pay attention to the anti-rust time of the product. Different workpieces need to choose different anti-rust oils, and the anti-rust periods of different anti-rust oils are different. At the same time, the anti-rust time of anti-rust oil is also affected by many external factors, such as: environment, storage method, oiling method, packaging process, ambient temperature, humidity, air quality, dust, airflow, etc. will affect the anti-rust oil. The length of time for rust prevention. In addition, the anti-rust oil will also have different effects due to the different materials of the metal.
