One of the pressing global issues we are facing today is climate change; a cryogenic Grade 1.4410 Duplex stainless steel with superior corrosion resistance and high strength properties, like”canyon apex”. In its annealed state, it is characterized by an approximately 50-50 ferrite-austenite ratio (which evolves with heat treatment). Duplex 25o7 is also widely used in many industrial applications including offshore oil platforms, chemical processing equipment and marine components.
This article explores Duplex 2507 stainless steel in depth — discussing its composition, properties, uses and more.
A Brief ExplanationDuplex 2507 Stainless Steel
What is Duplex 2507 Stainless Steel?Duplex 2507 (UNS S32750) is a super duplex stainless steel with carbon, chromium, nickel,and molybdenum. The key characteristics of duplex 2507 stainless steel is its combination of strength and excellent corrosion resistance, meaning this material is suitable for the ports that demand higher performance applications. Such applications include chemical process equipment, petrochemical industries and also in seawater equipments. This steel is especially resistant to chloride induced SCC. With high chromium, molybdenum and nitrogen content offering extremely good resistance to pitting, crevice and general corrosion.
Making of Duplex 2507 Stainless Steel
The manufacture of Duplex 2507 stainless steel is very much in line with the other modern high-alloy steels. In electric arc furnaces, scrap steel and selected alloy additions are melted. After the steel is molten, it then goes into an AOD (argon oxygen decarburization) converter where main processes occur – not only are we removing carbon but also sulfur and gases in solution.AOD process normally used for introduction of nitrogen into the steel. After that, the steel goes to ladle furnace where can be done some inclusions removal.
Once these preparatory steps were accomplished, the process then goes onto transferring molten steel into casting operation taking shapes of individual ingots (big metal blocks) and continuously cast billets or bloom-formed sections. These solid steel blooms or ingots are re-heated and pass through further reducing mills to achieve the desired thickness. A heat treatment with the purpose of obtaining a homogeneous internal structure cooling down (quenching) by water, is generally they way we achieve this uniformity internally process that results you see gathering actionability solution annealing is implemented.
The Duplex 2507 pipe materials can be hot forming or cold-formed. When hot forming, a temperature range of about 1024-1232 °C should be considered When the part has been hot formed followed by solution annealed with minimum temperatures in approximately 1052 to1125 ºC and quenched rapidly using water. This was a cold-forming activity, that bundles bmmoongs bending; deep drawing /rosier yes-extruding/ cider pressing/, and therefore also the solution annealing with subsequent quench-hardening.
How is Duplex 2507 Stainless Steel different from ordinary duplex steel?
A copy of 2507 stainless steel supersuper duplex. Duplex stainless steels are specialized type of ss with a microstructure comprising near equal proportions ferrite and austenim (1). It combines some of the best features of each phase. Thanks to this mix, duplex stainless steel is incredibly durable while also offering good corrosion resistance. Nevertheless, not all duplex steel grades provide the same anti-corrosion characteristics. The class is normally quite resistant to all types of corrosion, but s specific alloy, included as member of this group may perform no better than an austentic steel in a similar environment and with the same treatment. There are four families of duplex stainless steels depending on the PREN (Pitting Resistance Equivalent Number) range that these alloys belong to. Super duplex stainless steel fall in this category with a PREN number of 38-45
Duplex 2507 Stainless Steel Applications
Applications of Duplex 2507 stainless steel
- Desalination.
- Equipment for the oil and gas industry – offshore platforms, pipelines, well casings
- Chemical processing equipment to help process corrosive chemicals.
- Goes into pulp getting rid of equipment in the paper along with other industry.
- Applications : For PVC strippers in petrochemical industry
- Water desalination plants.
- Some typical examples are power industry equipment such as Flue gas Desulfurization (FGD) systems.
- Marine parts like ship propellors and shafts.
- Scrubbers etc. are pollution control equipment
- Fittings are very important parts for the connection and the control of fluids flow in pipelines or systems. Elbows, tees, stub-ends, returns and caps are known as butt-weld fittings among others (thus can be produced without causing welding defects).
Duplex 2507 Stainless Steel Chemical Composition
Table 1: Chemical Composition (Weight %) of Super Duplex 2507
| Name | 2507 |
| UNS | S32750; S39275 |
| En No. | 1.441 |
| C (max.) | 0.03 |
| Mn | 1.2 |
| Si | 0.8 |
| Cr | 24.0-26.0 |
| Ni | 6.0-8.0 |
| Mo | 3.0-5.0 |
| N | 0.24-0.32 |
| Cu | 0.5 |
| Other | S 0.020 max; P 0.035 max |
| PREN | 40-43 |
How Much Carbon Does Duplex 2507 Stainless Steel Contain?
Duplex 2507 stainless steel has a carbon content of not more than 0.03 by weight.
Duplex 2507 Stainless Steel Properties
Below are the physical and mechanical properties of Duplex 2507 stainless steel in Table:
Table 2: Super Duplex 2507 Steel Physical and Mechanical Properties
| Property | Value |
| Density (g/cm3) | 7.8 |
| Melting point (°C) | 1350 |
| Modulus of Elasticity (GPa) | 200 |
| Elongation (%) | 15 |
| Tensile Strength (MPa) | 795 |
| 0.2% Yield Strength(MPa) | 550 |
| Hardness (Brinell) | 310 |
What is the machinability of Duplex 2507 Stainless Steel?
Can say that the machinability of super duplex 2507 ranges from a minimum of about 10% to around only30%. This makes it difficult to machine. As machining Duplex 2507 stainless steel is more difficult than materials with higher machinability ratings, it will require much more cutting force and special tooling, such as carbide inserts or ceramic chips instead of a conventional high-speed tool.
So, is Duplex 2507 Stainless Steel Magnetic?
The answer is Yes, 2507 Duplex steel contain ferritic grains so it has some amount of magnetism.
Is Duplex 2507 Stainless Steel Weldable?
Yes. Welding Duplex 2507 can be done only through specification of the various welding methods like SMAW (shielded metal arc welding), PAW (plasma arc welding) and GTAW (gas tungsten arc weldig), FCW, SAW. Welding 2507 When welding is required, it should be performed within the qualified range in order to maintain corrosion resistance and toughness of base metal.
Preheating of 2507 is not always necessary and in general should be avoided. The interpass weld temperature must be kept below 100 °C to ensure integrity of the weld.
Will Duplex 2507 Stainless Steel Rust?
Yes. While it is considered to have strong resistance against corrosion, duplex 2507 stainless steel may rust in extreme circumstances. It is, however, less sensitive to rust compared some other grades of stainless steel. The elevated chromium and molybdenum supply of alloy 2507 makes it extraordinarily resistant to uniform corrosion with organic acids such as formic, acetic. Good Corrosion Resistance: 2507 steel welds and heat treated, with the addition of excellent corrosion resistance in a wide range corrosive environment as sea water,oil,mild acids etc where common stainless steels such as T316 /L can not be good resistant.
Duplex 2507 Stainless Steel Thermal Properties
- Table 3 – Thermal Properties of Duplex 2507 Stainless Steel
- Table 3: Thermal Properties of Duplex 2507 Stainless Steel
| Property | 2507 |
| Thermal Conductivity (W/m·K) | 19 at 20-100 ºC |
| Thermal Expansion (m/m·K) | 14.5 up until 300 °C |
| Specific Heat 0-100 °C (J/kg·K) | 460 |
DIFFERENT FORMS OF DUPLEX 2507 STAINLESS STEEL MATERIAL
Below are some of the standard forms in which Duplex 2507 stainless steel material is available, and each one are made from a slightly different process to best suit various industrial applications:
SheetMetal is the most common form of Duplex 2507 Stainless Steel that provides strength, durability and long-lasting quality. Applications include construction, manufacturing and marine applications.
We offer duplex plates in grades ASTM 2205/ S31803, and the ASTM A240 UNS-S32205 to any size required.Rather than use this product as a profile it is overwhelmingly cut out of plate prior being finished by way of grinding.
Manufacture of shaft, valve and fasteners can be easily done with its different cross-sectional shapes and sizes where you can work on as per your reaming size requirement. This particular grade bar provides a better design in components due to duplex 2507 configuration (two phases) which plays an important role when subjected force or load is applied.
2507 Stainless steel PIPE / TUBE (WELDED & SEAMLESS)
Welded and seamless pipes made from duplex 2507 stainless steel are widely used in the manufacture of products for these applications such as oil and gas industry, chemical processing industryand desalination equipment.
2507 Stainless steel Weld Wire
The welding wire manufactured from Duplex 2507 is purpose designed for applications requiring strength and corrosion resistance characteristics of the alloy in critical structural or repair work.
Duplex 2507 Stainless Steels Equivalents
Table 4 gives the comparison of Duplex 2507 stainless steel counterparts.
Duplex 2507 ASME Equivalents Table 4
QualificationUNS No.Euro_normeUNS Euro_nome
| Grade | UNS No. | Euronorm No. | Euronorm Name |
| 2507 | S32750 | 1.441 | X2CrNiMoN25-7-4 |
Why You Should Choose Duplex 2507 Stainless Steel
Benefits of Using Duplex 2507 Stainless Steel
- Very good pitting corrosion resistance with PREN > 43 This makes it much more resistant to corrosion than even stainless steel grades such as 254SMO. Duplex 2507 is also suitable for other types of corrosion including Stress Corrosion Cracking (SCC), crevice, and general pitting. The excellent corrosion resistance properties of Duplex 2507 are a combination of these attributes:These combined factors make it an ideal choice in many applications for operators within demanding environments.
- It has a double yield strength value compared to the 300 series stainless steel_IMETHOD The strengthened metal body parts allow for lighter gage steel sections and lower amounts of material usage in equipment built to perform under the same load conditions.
- The yield and tensile strength are twice as high compared to conventional stainless steels. The tang allows the plastic to flow onto both sides of a steel insert, resulting in greatly improved wear resistance.
CONS OF DUPLEX 2507 STAINLESS STEEL
A few of the most common drawbacks of Duplex 2507 stainless-steel consist of:
- One of the biggest worries with Duplex 2507 stainless steel is its composition, and how brittle phases such as alpha prime ( ) and sigma prime cretain temperature ranges. This can result in decreases of toughness and impact resistance – important attributes for structural applications that will see exposure to various temperatures.
- Because of its elevated ferrite content, Duplex 2507 stainless steel exhibits a characteristic Ductile-to-Brittle Transition Temperature (DBTT). This limits it to applications above ca. -50 °C hence making Perborate not ideal for cryogenic application i.e., very cold environment with temperature going below 0°C.
- The dual microstructure phase is to help resist stress corrosion cracking due to strong intermetallic compounds in the head of Duplex 2507 stainless steel and can become soft at annealing temperatures, which could potentially create warp during hot forming operations. It is important to keep the annealing temperature constant in order to reduce these sources of error.
- Duplex 2507 is resistant to the spectrum of fairly stable corrosion media and when utilized in lower-stress applications; however, it can be problematic as one cyclically encounters high stress or contamination by ferrous materials like those used for toughened steel bolts which are often thereafter not maintained during installation. Exposure to such contaminants is especially present in shipyards and industrial settings. Rising temperatures of seawater may create a higher risk for corrosion making it unusable in many marine applications.
- Super duplex stainless steel 2507 typically contains a super ferritic-austenitic structure consisting of ~50% austenite and ~50% fer-rite. Obtaining the equilibrium relationships of these phases in welded joints is difficult. This depends on such things as alloy content, filler metal used, welding thermal cycles and shielding gas. Potential root crack and stress relief heat treatment after multi-layer welding.
High Quality Super Duplex 2507 Stainless Steel vs Regular Stainless Steel
It varies from application to an another depending on the requirements. Duplex 2507 is known for its excellent corrosion resistance, especially in harsh environments containing chlorides. Austenitics are the easiest to weld and, at time of high strength (super duplex), this is also a negative aspect. Other standard stainless steel (above 304) is pretty great with corrosion resistance, but maybe no Duplex 2507 cannot perform in high corrosiveness. Because of the presence of austenitic and ferritic structures, duplex stainless steels provide two times strength compared to standard grades in this subclass – e.g. 100 ksi vs 200ksi — but they also benefit from synergies that enhance specific resistance against localized corrosion cases including pitting, crevice corrosion, stress cracking corrosion etc. As such, Duplex 2507 is often the preferred choice when corrosion resistance demands are high. But, super duplex stainless steel max temperature limitations are the facts. In addition, 2507 offers improved strength compared to common stainless steel grades with its higher range of yield strengths perhaps allowing the use of thinner material therefore reducing both costs and weight. This is not the case and you should know that 2507 as a material costs more just facing its major enhanced compound content and many other correspondents ask this question. Duplex 2507 also requires more finesse and experience to weld, as compared with regular grades of stainless steel which are simpler in this respect.
Duplex 2507 Stainless Steel Prices
- Duplex 2507 is an example of this, and it really does cost a lot. This is what its strong alloying content means, but it also results in extreme corrosion resistance befitting of harsh environments.
Do You Know The Difference Between Duplex 2507 Stainless Steel and Super Duplex steel
- Both, Duplex 2507 stainless steel and super duplex steel are from the family of SGD (Super Grade-Duplex) stainless steels. Super duplex stainless steels (PREN nos 40-45) are typically characterized by their dual-phase microstructure with roughly equal parts of ferrite and austenite phases.
- PREN is a numerical value primarily used to evaluate and compare corrosion resistance of different stainless steel alloy. This is particularly useful when determining the corrosion resistance of stainless steel to pitting, a localised form of attack leading ultimately to failure by formation on the metal surface BETWEENI. Others include Z100,4501, UR 52N+, and the spring. Each has it’s own make, properties and purposes.
DUPLEX 2507STAINLESS STEELDuplex 2205What is the difference?
- 2205, 2507: What is the Difference? ———However they either belong to different types of alloy, such as duplex stainless steel – 2205(UNS S31803/ UNS S32205) or superduplex materials-S32750 (alloy with AWS F53),Here will discuss what these stepping mark meanStrictly speaking you can not use them interchangeably. Twice the molybdenum, twice the chromium and added nitrogen make Duplex 2507 even stronger than we just described. The composition provides for a duplex microstructure which combines the properties of austenitic and ferritic grades, giving Duplex 2507 superior corrosion resistance and higher strength over 2205.
- Degree of strength- Duplex 2507 has the upper handaturity relative to duplex 2205 in physical properties. It has high yield strength, tensile strength and impact toughness. Though these benefits come at the price of diminished ductility.
- The differences in Chemical composition are crucial when it comes to the resistance against corrosion. The higher molybdenum and nitrogen content in Duplex 2507 gives it more resistance to corrosion, specifically with regards to chloride rich acidic conditions. The wear resistance is fair, the pitting corrosion and intergranular are good but not as much as Duplex 2205.
Duplex 2507 is a super duplex stainless steel and Zeron100 is also a high tensile strength version.
- Duplex 2507 and Z100 sample are composed of similar chemical compositions. Z100, being a form of lean super duplex stainless steel has higher fractional additions of copper and tungsten as compared to 2507. More importantly, the addition of copper in Z100 with a range from 0.5% to max 1.0%, makes this outstandingly resistant against corrosive attacks mainly included non-oxidizing acids as well mineral bases whilst oxidizers such as hydrochloric and sulfuric acid. The increase in copper content makes it even more resistant to corrosive environments.
Summary
- The same we covered in this article about duplex 2507 steel What is, their application and different properties. Find out more on how Daxun sourcing dual rated 2507 eliminates extra steps in the supply chain for duplex steel.
- This is where Daxun offers a broad array of manufacturing capabilities and other value-add services for all your prototyping & production needs. Locate us for additional details or a free quote today!
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