The properties of stainless steel are determined by both chrome and nickel. Without chrome, it is not stainless steel, and the amount of nickel determines the value of stainless steel.stainless steel pipe supplier
Stainless steel maintains luster in the air and does not rust because it contains a certain amount of chromium (not less than 10.5%), forms a strong oxide film on the surface of steel, and is insoluble in certain media.
After the addition of nickel, the performance of the stainless steel is further improved. It has good chemical stability in air, water and steam, and has sufficient stability in a variety of acids, bases and brine solutions, maintaining its corrosion resistance even at high temperatures or in low temperature environments.
According to the microstructure, stainless steel is divided into martensite, austenitic, ferrite and duplex stainless steel. Austenite has good plasticity, low strength, certain toughness, easy processing and molding, and no ferromagnetism.
Austenitic stainless steel was introduced in Germany in 1913 and has always played the most important role in stainless steel. Its production and usage account for about 70% of total stainless steel production and consumption. The steel number is also the most, so most of the stainless steel you often find on the day is austenitic stainless steel.
The well-known 304 steel is austenitic stainless steel. The previous Chinese national standard is 0Cr19Ni9 (0Cr18Ni9), which means that it contains 19% Cr (chromium) and 9% Ni (nickel). 0 means carbon content <=0.07%.
The way the Chinese national standard is expressed is that the elements contained in stainless steel are clear at a glance. As for 304, 301, 202, 4×4 square tubing etc., that is the name of the United States and Japan, but now everyone is used to this name.