2. Knocking method: Hold the screw with a screwdriver, and then knock the handle position of the screwdriver with a hammer. It needs to be knocked several times until the screw shows signs of loosening, and then unscrew it with a screwdriver.
3, corrosion method: everyone knows that cola is corrosive, pour cola on the rusty screw, after a period of time, the screw will be easily unscrewed.
4, cold shrinkage and thermal expansion method: first heat the screw, then cool it, so that the rusty screw can be easily unscrewed.
5, alcohol+white vinegar+detergent mixing method: mix alcohol+white vinegar+detergent, then pour it in the rusty place of the screw, let it stand for a while, and you can easily unscrew the screw.
Common methods to prevent iron from rusting
Alloying to change the internal structure of iron. For example, adding chromium, nickel and other metals to ordinary steel to make stainless steel greatly increases the rust resistance of steel.
Covering the surface of iron products with protective layer is a common and important method to prevent iron products from rusting. According to the composition of the protective layer, it can be divided into the following categories:
A, coating mineral oil, painting or firing enamel, plastic spraying, etc. On the surface of iron products. For example, cars and buckets are often painted; Machines are often coated with mineral oil.
B, plating a layer of metal that is not easy to rust, such as zinc, tin, chromium, nickel, etc. By electroplating, hot plating and other methods on the steel surface. A dense oxide film can be formed on the surface of these metals, thus preventing iron products from rusting when they come into contact with water, air and other substances.
C, chemically forming a dense and stable oxide film on the surface of the iron product to prevent the iron product from rusting.
Keeping the surface of iron products clean and dry is also a good way to prevent iron products from rusting.
How to remove rust
To remove rust, you can shovel it off with various tools, or soak it in acidic solution to dissolve it. After removing rust, the surface of iron must be treated, coated with a layer of lead and then painted; Or plated with other metals that are not easy to rust. A more thorough method is to add some other metals to iron to make stainless steel alloys. The stainless steel we are familiar with is an alloy made by adding a little nickel and chromium to steel.