What is 2507 duplex stainless steel

2507 stainless steel application:

2507 is a ferritic - austenitic (duplex) stainless steel, which combines a number of ferritic steels and most beneficial properties of austenitic steels, due to the steel chromium and molybdenum are high, it has a very good resistance to pitting, crevice corrosion and the ability to even corrosion resistance. bidirectional microstructure of the steel has the advantage to ensure high resistance to stress corrosion cracking, and high mechanical strength.

2507 stainless steel used in the oil and gas industry; such as offshore oil platform (heat exchanger tubes, water treatment and water supply systems, fire systems, sprinkler systems, steady water system; petrochemical equipment; desalination (desalination) equipment (and equipment the high-pressure pipe, water pipe); both require high strength while requiring high resistance to corrosion of mechanical and structural components; fuel (waste) gas purification equipment.

Content25Cr-7Ni-4Mo-0.27N

Standard

ASTM/ASME:A240 - UNS S32750

EURONORM:1.4410 - X2 Cr Ni MoN 25.7.4

AFNOR:Z3 CN 25.06 Az

DIN/EN 1.4410、ASME SA-240

Corrosion resistance:

  

  1. PittingCorrosion

SAF 2507 high chromium and molybdenum content has a strong ability towards organic acids, formic acid, acetic acid, etc. .SAF2507 also has resistance to inorganic acids, inorganic acids, especially those containing chlorides also has a strong corrosion resistance.

Compared to 904L, SAF2507 dilution mixed with sulfuric acid chloride ions have a stronger corrosion resistance .904L is alloyed austenitic specially designed to resist pure sulfuric acid.

316L grades can not be used in hydrochloric acid, which may be subject to localized corrosion or general corrosion .SAF2507 can be used in dilute hydrochloric acid, with a strong ability of anti-plaque and anti-crevice corrosion damage.

  1. Inter-granular corrosionresistance

SAF 2507 has low carbon content greatly reduces risk of inter-granular carbon precipitation during heat treatment; therefore, this alloy has the ability to resist the strong inter-related with carbide crystal corrosion.

  1. Stress Corrosion Cracking

SAF 2507 duplex structure has a strong ability to resist stress corrosion cracking. Because its higher alloy content, SAF 2507 corrosion resistance and strength are better than 2205.

Cracks in construction is almost inevitable, which makes stainless steel in chloride environments more susceptible corrosion ability .SAF 2507 with strong anti-corrosion crevice corrosion .SAF 2507 curve in sulfuric acid containing 2000ppm chlorine ions, etc. 0.1 mm / year; in hydrochloric acid and other corrosive curve of 0.1 mm / year.

Mechanical properties: SAF 2507 has a high compressive strength, impact strength and low thermal expansion coefficient and high thermal conductivity of these characteristics apply to many structural and mechanical components .SAF 2507 has high impact strength, not a prolonged period. temperatures above 570 ° F temperature environment, which may weaken its tensile strength and toughness: σb≥730Mpa; elongation:. δ≥20%

Supporting Welding: ER2594 wire, E2594 electrode

Application areas: pulp and paper industry, desalination, flue gas cleaning, heat exchangers, chemical tankers piping systems, water systems.

2507 available product specification

2507 stainless steel sheet and plate thickness: 0.3mm-350mm

2507 stainless steel bar diameter:3.0mm-500mm

2507 stainless steel wire diameter:0.1mm-20mm

SAF 2507 Welding performance

SAF2507 stainless steel can be processed through GTAW, GMAW, SMAW and SAW welding and other welding methods. 25.10.4L for GTAW welding method, 25.10.4LR and 25.10.4.LB for manual welding, when the welding work has high requirement on toughness, 25.10.4.LB alkaline electrode is to be applied. Recommendation for linear energy ranges from 0.2 to 1.5kJ / mm, in order to avoid rapid cooling, hot rolled plate welding generally use the upper limit. Cold rolled sheet is to apply lower limit. the control layer temperature should not exceeding 150 ℃. When GTAW welding method, using pure argon or Ar + 2% N2 protection.

Hot and cold processing

 

Thermoforming temperature range is limited, if the temperature is too low, less plastic ferrite steel will severely suffer from crack in the deformation zone; if the temperature is too high, steel may become so soft that it may suffer from broken down.Therefore, the temperature control is critical SAF2507 thermoforming (working) temperature range from 1200 to 1025 ℃. Workpiece thermal processing need water quenching. Duplex stainless steel in the solution temperature is very soft, if there is not enough support to the workpiece, twisting and deformation will occur, which is very important for large-diameter thin-walled pipe, twist reshaping or straightening products is very difficult.

 

SAF2507 stainless steel after cold forming, such as cold-formed, the amount of deformation is generally not more than 10% to 15%, does not require a subsequent heat treatment, but under conditions of harsh media or a relatively large amount of cold deformation, or to be 1050 ~ 1120 ℃ heating is followed by air cooling and water cooling.

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