Why are pure copper and stainless steel rusted? When brown rust spots (points) appear on the surface of pure copper and stainless steel pipes, people are very surprised: “Pure copper and stainless steel are not rusted, and rust must be of quality.” problem”. Tiesą sakant, this is a one-sided misconception about the lack of understanding of pure copper and stainless steel. Pure copper and stainless steel will also rust under certain conditions.
Pure copper and stainless steel have the ability to resist atmospheric oxidation – tai yra, rust, and also have the ability to corrode in acid, alkali, and salt-containing media – tai yra, corrosion resistance. However, the degree of corrosion resistance varies with the chemical composition of the steel itself, the state of addition, the conditions of use, and the type of environmental medium. For example, 304 steel pipe has absolutely excellent rust resistance in a dry and clean atmosphere, but it is moved to the coastal area, and it will soon rust in sea fog containing a lot of salt; while 316 steel pipe will perform. good. Todėl, it is not any kind of stainless steel that is resistant to corrosion and rust in any environment.
Stainless steel is a very thin and strong and stable chromium-rich oxide film (protective film) formed on the surface to prevent the oxygen atoms from continuing to infiltrate and continue to oxidize, thereby obtaining the ability to resist rust. Once for some reason, the film is continually destroyed, oxygen atoms in the air or liquid will continue to infiltrate or iron atoms in the metal will continue to separate out, forming loose iron oxide, and the metal surface will be continuously rusted. There are many forms of such surface film damage, and the following are common in daily life:
1. The surface of pure copper or stainless steel contains dust or other metal particles attached to other metal elements. In humid air, the condensation between the attached material and the stainless steel connects the two into a micro battery. In the electrochemical reaction, the protective film is destroyed, which is called electrochemical corrosion.
2. The surface of pure copper and stainless steel adheres to organic juice (such as melon, noodle soup, glutinous rice, etc.), and in the case of water and oxygen, it constitutes an organic acid, and the organic acid corrodes the metal surface for a long time.
3. The surface of pure copper and stainless steel adheres to acid, alkali and salt substances (such as alkali water and lime water splashing on the wall), causing local corrosion.
4. In polluted air (such as the atmosphere containing a large amount of sulfide, carbon oxide, nitrogen oxide), in the case of condensed water, sulfuric acid, nitric acid, acetic acid liquid point is formed, causing chemical corrosion.
All of the above conditions can cause corrosion of pure copper and stainless steel surface protective film and cause rust. Todėl, in order to ensure that the metal surface is permanently bright and not rusted, we recommend:
1. The surface of the decorative stainless steel must be cleaned and scrubbed frequently to remove the deposits and eliminate external factors that cause modification.
2. 316 stainless steel is used in the seaside area, ir 316 is resistant to seawater corrosion.
3. Some chemical components of pure copper and stainless steel pipes in the market cannot meet the corresponding national standards and cannot meet the requirements of 304 materials. Todėl, it will also cause rust, which requires the user to carefully select the products of reputable manufacturers.
Why is stainless steel magnetic?
People often think that magnets adsorb stainless steel, verify its pros and cons and authenticity, do not absorb non-magnetic, think it is good, the goods are genuine; if the attractor is magnetic, it is considered a counterfeit fake. Tiesą sakant, this is an extremely one-sided, unrealistic way of distinguishing mistakes.
Pure copper, stainless steel hardware maintenance tips
1. After the shower is finished, dry the faucet and the pole with a soft towel, as the remaining shower gel will erode the plating.
2. After the plating layer begins to rust, rub it with toothpaste around the rust spots.
3. In the bathroom, use as little acid cleaner as possible, and use less soap and other materials to scrub the faucet.
Pure copper, stainless steel rusty handling tips
1. Kerosene, tooth powder descaling method: first wipe it with cloth kerosene, then wipe it with tooth powder, and the copper rust can be removed.
2. Vinegar to embroider method: green copper rust on copper utensils, can be immersed in vinegar with cloth, and then add appropriate amount of salt or cuttlefish bone powder to wipe, you can remove.
3. Sea salt descaling method: If the corrosion on the copper ware is very serious, the sea salt can be placed in the melted wax and wiped with this solution to eliminate the copper rust.
4. Lemon juice descaling method: If the copper utensils are rusted, you can use lemon juice and salt to remove them. If you want to make them brighter, you can wipe them with tin foil or sawdust with cigarettes. The effect is very good.
5. Talc powder, fine wood descaling method: use 160 g of fine wood, 60 g of talcum powder, 240 of wheat bran and together, pour 50 g of vinegar, mix into a paste, coated in rusty copper On the device, after the wind is dried, the copper rust can be removed.