Views: 5 Author: Site Editor Publish Time: 2025-10-27 Origin: Site
As a professional supplier of steel tubes and fittings, duplex stainless steel products have always been one of our important businesses. Our old customer in Singapore is an important trading partner that we have been cooperating with for many years.In the order email sent to us in mid September, the customer clearly stated: "This time we need to purchase 2205 duplex stainless steel tubes and fittings. The project time is tight, and we must deliver on time and the product quality standards must not be lowered. We trust you with this order.
For our company's key customers, we have a dedicated service process that includes not only their procurement data over the years, but also their requirements and product details.
The final goods were delivered on schedule, and our documentation personnel pre booked the latest shipment to Singapore, seamlessly connecting with the delivery time and saving valuable transportation time for the customer.
ITEM | DESCRIPTION | QTY | UNIT |
1 | Barrel nipple DN15 BSPP - 2205 X 25mm | 8 | EACH |
2 | Concentric Reducer OD38.1 x 2mm X OD25.4 x 2mm - s2205 | 3 | EACH |
3 | Concentric Reducer OD73.03 x 3.05 X OD38.1 x 2mm - s2205 | 1 | EACH |
4 | ConcentricReducer OD50.8 x 2.0 X OD25.4 x 2mm - w2205 | 1 | EACH |
5 | Eccentric Reducer OD31.75 x 2mm X OD25.4 x 2mm - s2205 | 2 | EACH |
6 | Eccentric Reducer OD38.1 x 2mm X OD25.4 x 2mm s2205 | 10 | EACH |
7 | Eccentric Reducer OD50.8 x 2mm X OD25.4 x 2mm - s2205 | 5 | EACH |
8 | Eccentric Reducer OD50.8 x 2mm X OD31.75 x 2mm -s2205 | 4 | EACH |
9 | Eccentric Reducer OD73.03 x 3.05 X OD38.1 x 2mm -s2205 | 4 | EACH |
10 | Eccentric Reducer OD73.03 - 3.05 X OD50.8 x 2mm - s2205 | 5 | EACH |
11 | Eccentric Reducer OD88.9 - 3.05 X OD50.8 x 2mm - w2205 | 3 | EACH |
12 | Eccentric Reducer OD88.9 - 3.05 X OD73.03 -3.05 - w2205 | 13 | EACH |
13 | Eccentric Reducer OD31.75 x 2mm X OD25.4 x 2mm -s2205 | 1 | EACH |
14 | Eccentric Reducer OD38.1 x 2mm X OD25.4 x 2mm - s2205 | 4 | EACH |
15 | Eccentric Reducer OD50.8 x 2mm X OD31.75 x 2mm - s2205 | 1 | EACH |
16 | Eccentric Reducer OD50.8 x 2mm X OD25.4 x 2mm - s2205 | 1 | EACH |
17 | Eccentric Reducer OD50.8 x 2mm X OD38.1 x 2mm -s2205 | 1 | EACH |
18 | Eccentric Reducer OD73.03 x 3.05 X OD50.8 x 2mm - s2205 | 1 | EACH |
19 | Eccentric Reducer OD73.03 x 3.05 X OD38.1 x 2mm - s2205 | 1 | EACH |
20 | Eccentric Reducer DN125(OD141.3) - 3.4 X OD88.9 x 3.05 - w2205 | 2 | EACH |
21 | Eccentric Reducer OD73.03 x 3.05 X OD31.75 x 2mm - s2205 | 1 | EACH |
22 | Eccentric Reducer OD73.03 x 3.05 X OD50.8 x 2mm - w2205 | 1 | EACH |
23 | Tube 38.1 x 2mm x 6m -s2205-10 | 7 | LGTH |
24 | Tube 31.75 x 2mm x 6m -s2205-10 | 1 | LGTH |
25 | Tube 25.4 x 2mm x 6m -s2205-10 | 10 | LGTH |
26 | Tube 50.8 x 2mm x 6m -s2205-10 | 2 | LGTH |
27 | Elbow 45° SR OD73.03 x 3.05 (w2205) | 10 | EACH |
28 | Elbow 90° SR OD73.03 x 3.05(w2205) | 10 | EACH |
29 | Elbow 45° SR OD31.75 x 2mm - s2205 | 2 | EACH |
30 | Elbow 90° SR OD31.75 x 2mm - s2205 | 1 | EACH |
31 | Reducing Tee OD73.03 x 3.05 X OD38.1 x 2mm - s2205 | 1 | EACH |
32 | Socket DN15 BSPP - 2205 X 25mm | 8 | EACH |
33 | End Cap OD38.1 x 2mm - s2205 | 2 | EACH |
TOTAL | 127 | UNIT | |
In the construction of industrial pipeline engineering pipelines and fittings, duplex stainless steel pipes and fittings have excellent performance and have become an important component in fields such as chemical engineering, marine engineering, and energy.
Duplex Stainless Steel (DSS) refers to a type of stainless steel that contains both austenitic and ferritic phases in its microstructure at room temperature, with a roughly balanced proportion of the two phases (usually 40% -60% each). This special "dual phase" structure is not simply a mixture of two phases, but rather a synergistic effect formed through precise composition design (such as controlling the content of chromium, nickel, molybdenum, nitrogen, and other elements) and heat treatment processes - the austenite phase endows the material with excellent toughness, weldability, and formability, while the ferrite phase contributes to high strength, high thermal conductivity, and excellent stress corrosion resistance.
Compared with austenitic stainless steel, duplex stainless steel has significant advantages: in terms of strength, its yield strength can reach more than twice that of austenitic stainless steel, which can significantly reduce the thickness of structural components, lower the overall weight and manufacturing cost of equipment; In terms of corrosion resistance, especially the ability to resist pitting and crevice corrosion by chloride ions, it far exceeds ordinary 304 stainless steel and can even be comparable to high alloy austenitic stainless steel; At the same time, it also has good fatigue resistance and intergranular corrosion resistance, and can adapt to complex and harsh industrial environments. Therefore, it is widely used in fields that require extremely high material performance.
According to the differences in corrosion resistance, strength, and alloy element content, duplex stainless steel can be divided into three categories, each corresponding to different application scenarios to meet diverse industrial needs:
The representative grades are UNS S32101 (2101) and UNS S32202 (2202). The chromium content of this type of material is about 21% -23%, the nickel content is relatively low (1.5% -4.5%), and the strength and corrosion resistance are improved by adding nitrogen elements (0.14% -0.20%). Its yield strength can reach over 450MPa, and its resistance to pitting corrosion equivalent number (PREN) is about 24-29. It is suitable for scenarios with moderate corrosion resistance requirements and cost sensitivity, such as urban water supply and drainage pipelines, low concentration acid-base solution transportation equipment, etc.
Taking UNS S32205 (2205) and UNS S32550 (2550) as typical examples. The chromium content is increased to 22% -25%, the nickel content is 4.5% -6.5%, the molybdenum content is increased to 2% -3%, the PREN value reaches 32-38, and the resistance to chloride ion corrosion is significantly enhanced. At the same time, its yield strength remains above 480MPa, combining high strength and high corrosion resistance. It is currently the most widely used type of duplex stainless steel, covering multiple fields such as chemical engineering, marine engineering, and oil and gas extraction.
Representative grades include UNS S32750 (2507) and UNS S32760 (2760). This type of material has a chromium content of up to 24% -27%, a nickel content of 6% -8%, and a molybdenum content of 3% -5%. Some elements such as copper and tungsten are also added, and the PREN value exceeds 40. It can work stably in extremely harsh corrosive environments such as high concentration chloride solutions and high-temperature acidic oil and gas fields. Its yield strength can reach over 550MPa, but the manufacturing cost is relatively high, mainly used in high-end industrial scenarios such as deep-sea oil and gas extraction equipment, desulfurization and denitrification devices, etc.
Dual phase stainless steel products come in a variety of forms, including pipes, fittings, plates, forgings, etc. Different products have corresponding international universal standards to ensure consistency and reliability in product quality. The following are the material standards and corresponding materials for commonly used products in the industrial field:
ASTM A789/A789M: This is the core standard for seamless and welded duplex stainless steel tubes, suitable for pipeline systems transporting corrosive fluids. The duplex stainless steel materials covered by the standard include low alloy type S32101, medium alloy type S32205, high alloy type S32750, etc. It specifies the requirements for dimensional tolerances, mechanical properties, corrosion resistance tests (such as intergranular corrosion test and pitting corrosion test) of pipes, and is widely used in the chemical and petrochemical industries.
ASTM A815/A815M: A standard specifically designed for duplex stainless steel butt welded fittings (such as elbows, tees, reducers), covering materials including S32205 (WPS S32205), S32750, etc. The standard specifies the manufacturing process (such as hot pressing, cold forming), groove size, and non-destructive testing (UT, RT) requirements for pipe fittings, ensuring that the welding performance of the pipe fittings matches that of the pipes, and is suitable for connecting chemical pipeline systems.
ASTM A182/A182M: A standard applicable to forged stainless steel fittings such as flanges, valves, and joints. The duplex stainless steel materials are mainly F51 (corresponding to UNS S32205), F53 (corresponding to UNS S32750), and F60 (corresponding to UNS S32550). This standard has extremely high requirements for the chemical composition, mechanical properties, and forging process of forgings, emphasizing the density and uniformity of forgings, and is commonly used in key connection parts of high-pressure pipeline systems. 3.
ASTM A240/A240M is the primary standard for duplex stainless steel plates and strips, covering materials such as S32101, S32205, S32750, etc. The standard specifies the thickness deviation, mechanical properties (tensile strength, yield strength, elongation), bending test requirements, and surface quality grade of the sheet metal, and is applicable to the manufacture of shells and heads for equipment such as pressure vessels, storage tanks, and heat exchangers.
Among numerous duplex stainless steel products, ASTM A789 UNS S32205 tube, ASTM A815 WPS S32205 butt weld pipe fittings, and ASTM A182 F51 forged pipe fittings have become the "main force" in the industrial field due to their balanced performance and wide application. Their specific characteristics and properties are as follows:
UNS S32205 is a representative of medium alloy duplex stainless steel. Under the ASTM A789 standard, this pipe material has become one of the important pipes for chemical and marine engineering due to its combination of "high strength+high corrosion resistance".
Chemical Composition: chromium (22.0% -23.0%), nickel (4.5% -6.5%), molybdenum (2.0% -3.0%), nitrogen (0.14% -0.20%). The chemical element composition ratio ensures a balanced proportion of the two phases (austenite about 50%, ferrite about 50%).
| CHEMICAL | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A789 UNS 32205 | 0.03 max | 2.0 max | 0.030 max | 0.020 max | 1.0 max | 4.5-6.5 | 22.0-23.0 | 3.0-3.5 | 0.14-0.20 |
Mechanical Properties: yield strength ≥ 485MPa, tensile strength ≥ 655MPa, elongation ≥ 25%, hardness ≤ 290HB. Compared with ordinary 304 stainless steel (yield strength of about 205MPa), its yield strength is increased by more than twice, it can withstand higher working pressure, reduce pipe wall thickness, lower conveying resistance and installation costs.
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | HARDNESS |
| ASTM A789 UNS S32205 | 655 min | 485 min | 25 min | 290 max |
Corrosion Resistance: The equivalent number of pitting corrosion resistance (PREN=Cr%+3.3 × Mo%+16 × N%) is about 34, which has excellent resistance to chloride ion pitting and crevice corrosion. It can work in an environment below 60 ℃ for a long time in a sodium chloride solution with a concentration of ≤ 20%; At the same time, after sensitization treatment at 650 ℃ for 1 hour, the intergranular corrosion test (Method A) can still be conducted, and the resistance to intergranular corrosion is stable.
Application Advantages: Good welding performance. After welding with matching duplex stainless steel welding wire (such as ER2209), the two-phase ratio in the heat affected zone changes little, and the mechanical properties and corrosion resistance do not significantly decrease; And the inner wall of the pipe is smooth, with low fluid resistance, suitable for transporting corrosive media such as seawater, acid-base solutions, oil and gas.
WPS S32205 butt weld pipe fittings under ASTM A815 standard are the core connectors that match ASTM A789 S32205 pipes. They mainly include butt welded 45 degree elbows, 90 degree elbows, tees, reducers, pipe caps, and other types. Their performance matches the height of the pipe, ensuring the integrity and safety of the pipeline system.
Manufacturing Process: Hot pressing or cold forming process is adopted, and solution heat treatment (quenching and cooling at 1020-1100 ℃) is required after forming to ensure uniform microstructure of the pipe fittings, eliminate internal stress generated during the forming process, and avoid the risk of cracking during subsequent use.
Material Properties: yield strength ≥ 485MPa, tensile strength ≥ 620MPa, elongation ≥ 25%, completely consistent with the mechanical properties of S32205 pipe, ensuring that the strength of the welded joint is not lower than that of the pipe body; In terms of corrosion resistance, both the inner and outer surfaces of the pipe fittings have undergone acid pickling and passivation treatment, and their resistance to chloride ion corrosion is synchronized with that of the pipe.
Chemical Composition
| CHEMICAL | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A815 UNS 32205 | 0.03 max | 2.0 max | 0.030 max | 0.020 max | 1.0 max | 4.5-6.5 | 22.0-23.0 | 3.0-3.5 | 0.14-0.20 |
Mechanical Properties
| CHEMICAL | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A815 UNS 32205 | 0.03 max | 2.0 max | 0.030 max | 0.020 max | 1.0 max | 4.5-6.5 | 22.0-23.0 | 3.0-3.5 | 0.14-0.20 |
Application Features: The butt welding interface adopts a standard groove design, which can form a uniform weld seam when welding with the pipe, and the welding quality is easy to control; And the dimensional accuracy of the pipe fittings is high, ensuring the sealing of pipeline installation, suitable for scenarios such as chemical pipeline systems and offshore platform oil pipelines.
ASTM A182 F51 Socket Weld Fittings
ASME B16.11 Treaded Fittings
ASTM A182 F51 forged fittings correspond to UNS S32205 material, mainly including forged fittings, flanges (flat welding flanges, butt welding flanges), valve bodies, etc. Due to the high-density structure brought by the forging process, they have become key connectors under high pressure and high corrosion conditions.
Product Types: including threaded fittings and socket welded fittings, meeting the needs of different connection methods, widely used in terminal connections and valve installation of high-pressure pipeline systems.
Forging Advantages: Adopting free forging or die forging technology, the metal grains are refined through high-temperature forging (1100-1200 ℃), eliminating internal porosity, porosity and other defects. The density of the forging is ≥ 99.5%, significantly improving the fatigue resistance and impact resistance of the material - its impact energy (-40 ℃) is ≥ 40J, far higher than the performance level of cast pipe fittings.
Performance Indicators: yield strength ≥ 450MPa, tensile strength ≥ 620MPa, elongation ≥ 35%, mechanical properties consistent with S32205 pipe and butt welded pipe fittings; In terms of corrosion resistance, forgings have high chemical composition uniformity, no component segregation phenomenon, and can effectively resist crevice corrosion and stress corrosion cracking.
Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A182 F51 | MIN | 4.50 | 21.00 | 2.50 | 0.08 | |||||
| MAX | 0.03 | 2.00 | 0.030 | 0.020 | 1.00 | 6.50 | 23.00 | 3.50 | 0.20 |
Mechanical Properties
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | R/A % |
| ASTM A182 F51 | 620 min | 450 min | 35 min | 45 min |
Application Scenarios: Due to the high strength and reliability of forgings, ASTM A182 F51 forged fittings are mainly used in high-pressure pipeline systems, such as reaction kettle feed pipelines in the petrochemical industry, wellhead Christmas tree connection flanges in the oil and gas extraction industry, and cooling water pipeline valves in the nuclear power industry. They can work stably for a long time under pressure ≤ 16MPa and temperature -40 ℃ -300 ℃.
With excellent comprehensive performance, duplex stainless steel has penetrated into multiple industrial fields, from traditional chemical engineering to emerging energy, from land engineering to marine development. Its application scenarios continue to expand and become an important material support for promoting industrial upgrading
Chemical and Petrochemical Industry
Marine Engineering Field
Energy Sector
Municipal and Water Treatment Fields
Food and Pharmaceutical Industry
