Steel is an alloy with iron as the main component, and it appears more frequently around us than aluminum. Although this material is heavier than aluminum, it is easier to handle, and stainless steel sheets and other alloys are not easy to rust. In fact, a part of stainless steel sheet has both rust resistance and acid resistance (corrosion resistance). The rust resistance and corrosion resistance of stainless steel sheets are due to the formation of chromium rich oxide film (passive film) on its surface. The rust resistance and corrosion resistance are relative. The results show that the corrosion resistance of steel increases with the increase of chromium content in a weak medium such as atmosphere, water and oxidizing medium such as nitric acid.
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Definition of stainless steel sheet
Stainless steel sheet is a kind of steel, steel refers to the content of carbon (c) in less than 2% is called steel, more than 2% is iron. In the process of steel smelting, chromium (CR), nickel (Ni), manganese (MN), silicon (SI), titanium (TI), molybdenum (MO) and other alloying elements are added to improve the properties of the steel, so that the steel has corrosion resistance (i.e. no rust), which is commonly known as stainless steel sheet. Stainless steel sheet relies on a thin, firm, fine and stable chromium rich oxide film (passive film) on its surface to prevent oxygen atoms from permeating and oxidizing continuously, so as to obtain corrosion resistance. Its corrosion resistance and oxidation resistance are closely related to its chemical composition.
Generally speaking, steel with more than 10.5% chromium is not easy to rust. The higher the content of chromium and nickel, the better the anti-corrosion performance. For example, the content of nickel in 304 material should be 8-10%, and the content of chromium should reach 18-20%. Such stainless steel sheets will not rust in general.
Does stainless steel sheet not rust? Otherwise, stainless steel sheets will rust.
Stainless steel sheet has the ability to resist atmospheric oxidation, that is, the performance of stainless steel sheet, but also has the ability to resist corrosion in the medium containing acid, alkali and salt, that is, corrosion resistance. However, the corrosion resistance of the steel varies with its chemical composition, mutual state, service condition and environmental medium type. Once there is some reason, this kind of film is constantly damaged, and oxygen atoms in air or liquid will continuously penetrate or iron atoms in metal will continuously separate out, forming loose iron oxide, which is stainless steel sheet rusting. Generally, stainless steel sheet is easy to rust in the environment with high humidity, high pH in the air or in the solution with high pH.
Of course, the smelting process of steel plant sheets will also affect the corrosion resistance of stainless steel sheets. Good smelting technology, advanced equipment, advanced process, good control of alloy element proportion, high impurity removal ratio, good control of billet cooling temperature are not easy to rust. If the surface is damaged, it is easy to rust.
Simple classification of stainless steel sheet
Stainless steel sheet can be roughly divided into three categories: 200 series, 300 series and 400 series. Among them, the 300 series is the most commonly used. 200 series and 400 series are substitutes for 300 series. Strictly speaking, 400 series is not called stainless steel sheet, but stainless iron. Because it does not contain nickel, it can be attracted by magnets. The 200 series and 300 series are made of nickel, so they are not magnetic and cannot absorb iron.
304 is the most common variety in the 300 series, so the price trend of stainless steel sheets can be judged from the price change of 304. The 200 series contains less nickel, the 400 series contains no nickel, and the 300 series contains the most nickel, so the 300 series is the most affected by the nickel price.
300 series can be divided into 304, 304L, 316, 316L, 321, 309S, 310S and so on. The basis of differentiation is that the contents of various metal elements are different, and the characteristics of stainless steel sheets with different contents are also different. The difference between 304 and 304L lies in the different carbon (c) content. The one with L means low carbon, also called low carbon. The difference between 316 and 316L is the same.
There are many different kinds of stainless steel plates, Jiangsu C.J.M Stainless Steel Group has a complete range of stainless steel plates, to meet the needs of all parties. If you want to have more choices, please come to our company to choose! Tel. + 86-18092577236, post office postmaster@ssplatechina.com.
