With the continuous development of the industry, the use of steel is also increasing, but in the production process or the sealing process of finished products, steel plates are easily oxidized and rusted when exposed to humid air and rainy days, which affects the appearance quality of products. This creates problems for the use of steel, and the annual loss of steel due to corrosion is staggering.
According to statistics, the world's annual loss of steel due to corrosion is equivalent to about 30% of the annual output. Not only that, the equipment will also be damaged due to corrosion, causing shutdowns and production shutdowns, reducing product quality and causing huge losses to social wealth. Rust is the enemy of steel, so how to protect steel, prevent it from rusting and deterioration, and increase its service life has become a topic of general concern. Metals are divided into non-ferrous metals and ferrous metals, and ferrous metals include iron, manganese, and chromium. Iron is hard and ductile, has strong ferromagnetism, good plasticity and thermal conductivity, and is widely distributed on the earth. Various alloys with iron as the main body include cast iron, carbon steel, stainless steel, etc., and are widely used.
Water-based rust inhibitor for ferrous metals is a water-based anti-rust solution that can effectively protect steel, iron and other materials from rusting.
Water-based rust inhibitor for ferrous metal
Water-based rust inhibitors for ferrous metals are generally composed of corrosion inhibitors, complexing agents, alkalis, and wetting agents. The substance that plays a central role in the rust prevention process is the Corrosion Inhibitor. Different corrosion inhibitors have different corrosion inhibition mechanisms. With different corrosion inhibitors, the rust prevention performance is very different. Common inorganic corrosion inhibitors include sodium nitrite, sodium molybdate, sodium tungstate, boric acid, borax, phosphate, etc., which are all anodized corrosion inhibitors. There are more types of organic corrosion inhibitors, such as the well-known carboxylates: monocarboxylic acid, dicarboxylic acid, tricarboxylic acid, etc., in addition to fatty acid amides, borate esters, petroleum sulfonates , alkyl succinic acids, cationic quaternary ammonium salts, etc. This kind of corrosion inhibitor contains elements with lone pair electrons such as nitrogen, phosphorus, sulfur, oxygen, etc., which can directly form a chemical adsorption layer on the metal surface, and belong to the mixed corrosion inhibitor.
Common complexing agents include EDTA, phosphate, etc. The amount and type of complexing agent added have a great influence on the anti-rust performance. The complexing agent chelates with calcium and magnesium ions in water, and the corrosion inhibitor forms sodium or potassium salts with free sodium and potassium ions. Monovalent sodium salts and potassium salts themselves foam, and their adsorption performance is not as good as that of divalent salts, and the reduction in adsorption performance weakens the rust prevention performance. Only a few complexing agents can enhance rust resistance. Wetting agents play a role in reducing surface tension and improving the wetting performance of rust inhibitors. Most of the corrosion inhibitors themselves have a certain surface activity, so there is generally no need to add wetting agents. The analysis of ferrous metal rust inhibitor plays a crucial role in the research and development of rust inhibitor. For example, infrared spectroscopy is widely used in the qualitative analysis of small molecules and polymer compounds, which is a relatively simple and fast analysis method; nuclear magnetic resonance can analyze and test corrosion inhibitors in rust inhibitors; gas chromatography-mass spectrometry can It is used to analyze volatile solvents in rust inhibitor samples; liquid chromatography-mass spectrometry is used to characterize polar compounds in rust inhibitors, including: organic corrosion inhibitors, inorganic corrosion inhibitors, complexing agents, etc. Liquid ion chromatography can analyze inorganic ions in aqueous corrosion inhibitors. With the increasing requirements for anti-rust performance and environmental protection in industries such as machining, the anti-rust performance of water-based anti-rust agents has also improved. The key component is the type and combination of corrosion inhibitors. There are various types of corrosion inhibitors, and it is difficult to analyze accurately according to a single instrument, or it is necessary to carry out joint analysis of multiple equipments in order to obtain an accurate analysis data.
