stainless steel
Stainless steel is the general term of stainless steel and acid resistant steel.
Stainless steel refers to the steel which is resistant to the corrosion of weak medium such as atmosphere, steam and water, while the acid resistant steel refers to the steel that is resistant to the corrosion of chemical etching medium such as acid, alkali, salt, etc.
Stainless steel has a history of more than 90 years since it came out at the beginning of this century. The invention of stainless steel is a great achievement in the world metallurgical history. The development of stainless steel has laid an important material and technical foundation for the development of modern industry and scientific and technological progress. There are many kinds of stainless steel with different properties. In the process of development, several kinds of stainless steel have been formed.
According to the structure, it can be divided into martensitic stainless steel (including precipitation hardening stainless steel), ferritic stainless steel, austenitic stainless steel and austenite plus ferrite duplex stainless steel;
According to the main chemical composition of steel or some characteristic elements in steel, it can be divided into chromium stainless steel, chromium nickel stainless steel, chromium nickel molybdenum stainless steel, low carbon stainless steel, high molybdenum stainless steel, high purity stainless steel, etc;
It can be divided into stainless steel, stainless steel and stainless steel according to their corrosion resistance;
According to the functional characteristics of steel, it can be divided into low temperature stainless steel, non-magnetic stainless steel, free cutting stainless steel, superplastic stainless steel, etc.
At present, the commonly used classification method is based on the structure and chemical composition of steel and the combination of the two. It is generally divided into martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, duplex stainless steel and precipitation hardening stainless steel, or chromium stainless steel and nickel stainless steel. Stainless steel is generally used for anticorrosive Corrosive environment, as well as Yi therapy equipment and daily necessities


Stainless iron
Generally speaking, stainless iron is not easy to rust iron, in fact, a part of stainless iron, both rust resistance and acid resistance (corrosion resistance). The rust resistance and corrosion resistance of stainless iron are due to the formation of chromium rich oxide film (passive film) on its surface. This rust resistance and corrosion resistance are relative.
The results show that the corrosion resistance of iron increases with the increase of chromium water content in the weak medium such as atmosphere, water and nitric acid. When the chromium content reaches a certain percentage, the corrosion resistance of iron changes suddenly, that is, from easy to rust to not easy to rust, from corrosion resistance to corrosion resistance.
There are many ways to classify stainless iron.
According to the structure at room temperature, there are martensite, austenite, ferrite and duplex stainless iron;
According to the main chemical composition, it can be divided into two major systems: chromium stainless iron and chromium nickel stainless iron;
According to the use, there are stainless iron resistant to nitric acid, sulfuric acid, seawater, etc
The types of corrosion resistance can be divided into pitting corrosion resistant stainless iron, stress corrosion resistant stainless iron and intergranular corrosion resistant stainless iron;
According to the functional characteristics, it can be divided into non-magnetic stainless iron, easy cutting stainless iron, low-temperature stainless iron, high-strength stainless iron and so on.
Due to its excellent corrosion resistance, formability, compatibility and strength and toughness in a wide temperature range, stainless steel has been widely used in heavy industry, light industry, daily necessities industry and building decoration industry.