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What are the characteristics of Super duplex 2507 stainless steel pipe?
Super duplex 2507 pipe is also called two-way stainless steel. It combines the most beneficial properties of many ferritic and austenitic steels. Because of its high content of chromium and molybdenum, it has excellent resistance to spot corrosion, crevice corrosion and uniform corrosion. The bi-directional microstructure ensures that the steel has high resistance to stress corrosion cracking and high mechanical strength.
A remarkable feature of Super Duplex 2507 pipe is its duplex structure. In addition, it is often accompanied by the formation of other phases, which also affect the properties of steel more or less. For dual-phase steel, the special alloy element composition is the basis to ensure the composition of dual-phase and the proportion of each phase. Through the content of main elements, the phase proportion of the metallographic group can be predicted. At present, the WRC-92 organization chart proposed by the American Welding Research Association WRC is widely used internationally.
Super duplex 2507 pipe has strong resistance to local pitting, pitting and crevice pitting corrosion, mainly due to the role of Mo, N and other elements in the chemical composition. After years of research, a pitting equivalent index PREN has been established to evaluate. The higher the value, the stronger the ability to resist local pitting.
Super Duplex 2507 Stainless Steel pipe is a typical N, ultra-low carbon, dual-phase ferritic-austenitic stainless steel with excellent corrosion resistance and mechanical functions, and is widely used in oil and gas, petrochemical and marine engineering. However, during the hot rolling process, the 2507 stainless steel pipe has been in the two-phase zone, resulting in poor hot working function and simple edge crack defects, which severely limits the production of this stainless steel.
At present, there have been many reports on the study of the high-temperature rheological curve and thermoplasticity of 2507 duplex stainless steel pipes, but there are few reports on the study of the high-temperature thermoplasticity of the edge samples of the continuous casting slab of Super Duplex 2507 stainless steel tubes produced in industry. A company took the edge sample of the continuous casting slab of 2507 stainless steel tube as the research object to carry out the high-temperature tensile test, understand the change rule of the steel's thermoplasticity with the temperature, investigate the metallographic arrangement and fracture description of the samples at 950, 1000, 1050, 1100 and 1150 ℃, and provide the theoretical basis for the hot rolling process of 2507 duplex stainless steel tube.
The continuous casting billet is subject to low-order corrosion, and the corrosion agent is ferric chloride plus hydrochloric acid solution. Considering that the columnar crystal zone is less thermoplastic than the equiaxed crystal zone, the columnar crystal zone sample is selected. Process the sample into Φ 5mm × 69mm high temperature tensile specimen. The two ends of the sample are machined into M10mm general threads, which is convenient for fixing the sample.
With the rapid development of the stainless steel industry, we can understand the characteristics and application range of 2507 Super duplex stainless steel: 2507 duplex steel has high chromium and molybdenum content, and has strong overall corrosion resistance to organic acids such as formic acid and acetic acid. 2507 duplex stainless steel for power plant desulfurization and denitrification FGD system, industrial cleaning system, absorption tower and other energy industries; Mechanical parts with high strength, corrosion resistance and wear resistance. 2507 duplex stainless steel in petroleum and natural gas industry equipment: offshore platform, heat exchanger, underwater equipment, fire fighting equipment; Chemical processing industry, appliances and pipelines; Seawater desalination, high-pressure reverse osmosis equipment and submarine pipelines: 2507 super duplex steel has high chromium and molybdenum content, and has strong overall corrosion resistance to organic acids such as formic acid and acetic acid. 2507 duplex stainless steel for power plant desulfurization and denitrification FGD system, industrial cleaning system, absorption tower and other energy industries; Mechanical parts with high strength, corrosion resistance and wear resistance. 2507 super duplex stainless steel in petroleum and natural gas industry equipment: offshore platform, heat exchanger, underwater equipment, fire fighting equipment; Chemical processing industry, appliances and pipelines; Seawater desalination, high-pressure reverse osmosis equipment and subsea pipeline