Development process and application industry of duplex stainless steel

by yane Yang Sales Manager

The corrosion resistance of duplex stainless steel and corrosion fatigue performance is outstanding, widely used in equipment made of refining and chemical industry, salt industry and other industries in the atmospheric vacuum distillation unit and catalytic cracking and hydrocracking, continuous sulfate cooking or intermittent cooking device, compressor cooler operation environment is very bad.

In spite of the late appearance of this material, the development of the duplex stainless steel is very rapid. Because of its both austenitic stainless steel and ferritic stainless steel advantages in, and also make up the shortcomings of their respective, so the international attaches great importance to the development and production of duplex stainless steel, especially in the last century after 70s, with the advent of refining equipment, began production of duplex stainless steel equipment based on ultra low carbon n, the more broad road is prompted to enter the rapid development of dual phase stainless steel. Now duplex stainless steel has been combined with austenitic stainless steel, ferritic stainless steel and martensitic stainless steel as an independent large class of steel. In Europe, America and other countries, the development is very fast.

But our country began developing duplex stainless steel in the middle of 70s of last century, and because of the difficulty of production of duplex stainless steel, it developed slowly in China at that time. Later, with the mass production of stainless steel used VOD furnace, AOD furnace and large vacuum induction furnace, the domestic duplex stainless steel has also developed rapidly.

Below is the application field of the lower double phase stainless steel in China.

In the oil refining industry, used to make the CDU duplex stainless steel, including the lining, tower components, often air cooler, cut the top of wet air cooler and cut the top after the cold water cooling tube; there is a catalytic cracking unit, including catalytic absorption desorption tower tray, pipe lining, etc., gasoline reheat; there is a hydrocracking unit, including air cooler, desulfurization reactor, water cooler heat exchange tube.

In the petrochemical industry, double phase stainless steel will be used to made of polyvinyl chloride (PVC) and stripper heat exchanger; coil type oxygen chloride reactor, vinyl chloride vinyl chloride in the reboiler; methanol synthesis reactor, material / effluent heat exchanger, top condenser pressure flash tank; oxo alcohol pipe type loop reactor; acetic acid and other organic acids (formaldehyde and formic acid) production equipment and pipeline.

In land and offshore oil and gas industry, duplex stainless steel is used for conveying pipes and collecting pipes, offshore oil platform heat exchangers, water treatment and water supply systems, fire fighting systems, sprinkler systems and water stabilizing systems.

In the field of pulp and paper industry, the continuous sulfuric acid cooking or batch cooking device is used, or chlorine dioxide bleaching cartridge is mainly made of duplex stainless steel with excellent mechanical properties, wear resistance, corrosion fatigue and stress corrosion resistance.

The dual phase stainless steel is also used in the chemical fertilizer industry, in which the urea industry, the compressor cooler pipeline. Ammonium methylamine pump body. Stripper gas pipe, condensing high-pressure condenser tube, high-pressure decomposition tower pipe and pipeline decomposition. In the phosphoric fertilizer industry, it is used to reflect the tank, slurry pump and slurry pipeline.

The last use is high strength structural parts, mainly on the oil platform, such as the tensioning system of the derrick, the submarine pipeline, and the steam turbine blades, barges and so on.

Source: China Duplex Stainless Steel Pipe Fittings Manufacturer - Yaang Pipe Industry Co., Limited (www.yaang.com)