Simple classification of stainless steel Stainless steel can be roughly divided into three categories: 200 series, 300 series and 400 series, of which 300 series is the most commonly used, 200 series and 400 series are substitutes for 300 series to a certain extent, and strictly speaking 400 series The series is not called stainless steel, but stainless iron. Because it does not contain nickel, it can be attracted by magnets. The 200 series and 300 series have nickel, so they are not magnetic, and they can't attract iron.

304 is the most common variety in the 300 series, so the price trend of the entire stainless steel can generally 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 price of nickel.

The 300 series can be divided into 304, 304L, 316, 316L, 321, 309S, 310S, etc. The distinction is based on the content of various metal elements, and the characteristics of stainless steel with different contents are also different. The difference between 304 and 304L is that The carbon (C) content is different. The one with L means low carbon content, also called low carbon. The difference between 316 and 316L is the same.

Morphological classification of stainless steel Stainless steel can be divided into five categories: coils, plates, profiles, steel pipes and parts, the most important being coils and plates. Profiles are materials of various shapes made of plates, such as angle steel, flat steel, I-beam, and channel steel. Steel pipe mainly refers to seamless steel pipe, and the opposite of seamless steel pipe is welded pipe, the difference is whether it is formed at one time. Parts mainly refer to elbows and flanges and other small things.

The coil and the sheet are actually the same, but the form is different from the factory. If it is, it cannot be rolled, generally more than 16 mm can not be rolled.

There are coils, there are boards, and many times it is boards. The prices of coils and boards are also different. If it is purchased coils, it is calculated according to the actual weight, so the price is high. The board is calculated according to theory, and the price is low. , the reason is that there is a difference. For example, the thickness of 10mm may actually be 9.6mm, and there will be a price difference in the middle.

The stainless steel plate is divided into hot rolling and cold rolling according to the different rolling process of the rolling mill (the rolling mill is the machine name of the rolling plate), and the hot rolling is usually marked as NO. To be bright, close to the mirror, the best is the mirror surface, the mirror surface is not in stock and needs to be processed), for example, 304 is often purchased board, which means that the roll must be opened and flattened by the machine. It can be opened into different lengths by opening the leveling machine. If it is not a conventional length, it is called a fixed opening, which means a fixed opening size, because customers often put forward different length requirements according to actual needs. At this time, the roll is important. The board can not meet the requirements.

Domestic cold-rolled sheets are generally below 3 mm, and hot-rolled sheets are generally above 3 mm. There are both hot-rolled and cold-rolled sheets with a thickness of 3 mm, but the thickness of imported cold-rolled sheets can reach below 4 mm or even below 6 mm. Hot-rolled plates from 3 mm to 12 mm are called medium plates, and those above 12 mm are called thick plates, which can be thicker than 120 mm, and are also called hot-rolled medium and heavy plates, while cold-rolled plates are cold-rolled thin plates.