Duplex stainless steel and nickel base alloy are special stainless steel. First of all, they are different from ordinary stainless steel in chemical composition. They are high alloy stainless steel with high nickel, high chromium and high molybdenum.
According to the microstructure of stainless steel, duplex stainless steel can be divided into duplex ferritic stainless steel, duplex austenitic stainless steel, duplex martensitic stainless steel and super duplex stainless steel.
On the basis of ordinary austenitic stainless steel, through improving the purity of alloy, increasing the quantity of beneficial elements, reducing the C content, preventing the intergranular corrosion caused by precipitation of Cr23C6, good mechanical properties, technological properties and local corrosion resistance are obtained, and Ti stabilized stainless steel is replaced.
This kind of steel was developed in the late 1980s, and its brands mainly include SAF2507, ur52n, zeron 100, etc. it is characterized by low C content, high Mo and N content, ferrite content of steel accounts for 40% - 45%, and it has excellent corrosion resistance.
1. Ocean: marine structure of sea environment, desalination, mariculture, heat exchange of sea water, etc.
2. Environmental protection: flue gas desulfurization device of thermal power generation, waste water treatment, etc.
3. Energy field: atomic power generation, comprehensive utilization of coal, tidal power generation, etc.
4. Petrochemical industry: oil refining, chemical and chemical equipment, etc.
5. Food field: salt making, soy sauce brewing, etc.
In the above many fields, ordinary stainless steel 304 is not competent. In these special fields, special stainless steel is indispensable and irreplaceable. In recent years, with the rapid development of economy and the continuous improvement of industrial level, more and more projects need higher grade stainless steel special stainless steel (super stainless steel, nickel base alloy)
