Application of Duplex Stainless Steel Pipe in Desalination

Application of Duplex Stainless Steel Pipe in Desalination

Due to the high chloride ion concentration in seawater, equipment and pipelines of seawater desalination systems will face severe corrosion. Traditional Austenitic Stainless Steel Pipe often suffers local corrosion damage such as pitting, crevice corrosion, and stress corrosion. Duplex stainless steel happens to be in the above-mentioned corrosion. Excellent performance in the type, becoming one of the main materials. Among them, the evaporator condenser tube in the multi-stage flash seawater desalination method mostly uses 2507 super duplex stainless steel tubes instead of titanium or copper-nickel alloy, and the shell of the flash chamber can be 2205, which has been adopted by the Libyan desalination plant. The high-pressure pipeline of the reverse osmosis method and the high-pressure pump in a high chloride environment use 2507 steel, which is comparable to 6Mo super austenitic stainless steel.

Duplex Stainless Steel Pipe

The application status of casting Duplex Stainless Steel Pipe

The application of duplex stainless steel in China's shipbuilding industry is earlier, and it is also one of the most important industries in China. In the use of marine duplex stainless steel in our country, such as cargo bulkheads, piping and other components, the shapes are mostly plates, strips, tubes, etc., which are suitable for rolling or forging processes, and the technological development in this area is relatively mature. However, there are some components with complex shapes, such as valve bodies, impellers, guide vanes, etc., which are suitable for casting, and there are fewer reports on the research and application of cast duplex stainless steel for nuclear power, marine, and marine engineering.

At present, there are still relatively few grades of cast duplex stainless steel for marine use in China. The production technology of rolling and forging materials of existing duplex stainless steel are relatively mature, but some basic data such as upper and lower limits of the chemical composition of cast duplex stainless steel, Casting performance (fluidity, linear shrinkage and volume shrinkage, etc.), corrosion resistance, mechanical properties, technical indicators, and even heat treatment processes, simply apply the technical indicators of duplex stainless steel rolled and forged materials, and further development of casting dual Phase stainless steels, especially high-nitrogen cast super duplex stainless steels with higher corrosion resistance and mechanical properties have worked out chemical compositions and preparation processes that meet the technical requirements of castings. Some problems in casting duplex stainless steel, such as gas sensitivity, have not been fully understood, and further research and analysis are needed.

With the deepening of the research on the microstructure and related the corrosion resistance of cast duplex stainless steel, and the development of modeling materials and as-cast welding repair materials corresponding to the material, the cast duplex stainless steel will be widely used in petrochemical pipelines that require high corrosion resistance, Chemical industry, papermaking, construction, offshore platform, energy, freshwater treatment and other industrial fields.

In addition, thanks to the addition of copper to further improve the strength and corrosion resistance, duplex stainless steel has been used to manufacture containers for 7000 meters of deep seabed equipment and cables, and also used to manufacture seabed locators and controlled deep-sea acoustic release transponders Pressure housing and load-bearing components. We are Welded Pipe Stainless Steel Supplier, welcome to consult.