Duplex steel is a high performance alloy that has excellent strength & corrosion resistance. They are Made from a balanced microstructure of austenite & ferrite grade materials. Due to this unique structure of duplex stainless steel material, it offers superior mechanical strength as compared to the standard austenitic stainless steel. They are mainly used in industries such as oil & gas, chemical processing, marine & construction. Its dual phase structure not only improve toughness over ferritic grades but also makes it a cost-effective solution to use instead of high-nickel alloys.
Understanding Duplex Stainless Steel ASTM Grades
The American Society for Testing & Materials (ASTM) is a globally recognized organization known for developing & publishing standards for a wide range of materials. ASTM standards that start with the letter A usually apply to metals, including different types of stainless steel. ASTM A182 standard of duplex stainless steel is titled “Standard Specification for Forged or Rolled Alloy, Stainless Steel Pipe Flanges, Forged Fittings & Valves for high performance Service.” It is used as a duplex stainless steel ASTM grade to design the products to use in high temperature or pressure applications. The duplex stainless steel ASTM code uses the F prefix to indicate forged components. Few commonly used duplex stainless steel grades under this standard include ASTM A182 F51, F53, F55 & F61. These grades are known for their balanced austenitic ferritic microstructure to offer superior strength, toughness & corrosion resistance. At Kalpataru Piping Solutions, we offer a complete range of duplex stainless steel materials manufactured in compliance with the latest ASTM A182 standards.
Types of Duplex Stainless Steel ASTM Grades
- ASTM A182 F51 (UNS S31803 / S32205)
ASTM A182 F51 contains mainly 22% chromium of duplex stainless steel which is known as UNS S31803. Its composition supports pitting corrosion resistance for developing UNS S32205 which is known as F60. This improved grade can be dual certified as S31803. F51 & F60 together make up around 80% of all duplex stainless steel material due to their high strength & corrosion resistance.
- ASTM A182 F53 (UNS S32750)
Known as SAF 2507 or ASTM A182 F5 having 25% chromium super duplex stainless steel to offer superior pitting resistance & higher yield strength compared to F51. Used for applications that require both high mechanical strength & strong resistance to corrosion.
- ASTM A182 F55 (UNS S32760)
ASTM A182 F55, also known as UNS S32760 is a 25% chromium super duplex stainless steel with added tungsten to improve strength & corrosion resistance. Initially developed as Zeron 100, it is now commonly used in the chemical, offshore & shipping industries to make it durable for use in high pressure applications.
- ASTM A182 F61 (UNS S32550)
Originally known as Ferralium 255, ASTM A182 F61 (UNS S32550) is another super duplex stainless steel grade. It offers a higher minimum yield strength (85 ksi) & includes up to 2.0% copper, which enhances its pitting corrosion resistance. This makes it highly suitable for aggressive environments such as chemical processing facilities and saltwater exposure.
Chemical Composition of Duplex Stainless Steel ASTM Grades
| Trade Name | UNS | Chemical Composition | Min.Tensile(KSI) | Min.Yield(KSI) | Elongation% | Super Duplex American Standards |
| SAF 2507® | UNS S32750 | C 0.030 max Cr 24.0-26.0 Cu 0.5 max Mn 1.20 max Mo 3.0-5.0 N 0.24-0.32 Ni 6.0-8.0 P 0.035 max S 0.020 max Si 0.8 max |
116 | 80 | 15 | ASTM A182 F53, A240, A276, A479, A789, A790, A815, A928, A988 SAE J405 |
| – | UNS S32760 | C 0.03 max Cr 24.0-26.0 Cu 0.5-1.0 Mn 1.0 max Mo 3.0-4.0 N 0.2-0.3 Ni 6.0-8.0 P 0.03 max S 0.01 max Si 1.0 max W 0.5-1.0 |
109 | 80 | 25 | ASTM A182 F55, A240, A276, A314, A473, A479, A789, A790, A815, A928, A988 SAE J405 |
| SAF 2205®22Cr | UNS S31803 | C 0.30 max Cr 21.0-23.0 Mn 2.00 max Mo 2.50-3.50 N 0.08-0.20 Ni 4.50-6.50 P 0.030 max S 0.020 max Si 1.00 max |
90 | 65 | 25 | ASME SA-182 (F51), SA-240, SA-798, SA-790, SA-815 ASTM A182 (F51),A240, A276, A479, A789, A790, A815, A928,A988 SAE J405 |
| SAF 2205®22Cr | UNS S32205 | C 0.30 max Cr 22.0-23.0 Mn2.00 max Mo 3.00-3.50 N 0.14-0.20 Ni 4.50-6.50 P 0.030 max S 0.020 max Si1.00 max |
95 | 65 | 25 | ASME SA-182 (F60), SA-240, SA-798, SA-790, SA-815 ASTM A182 (F60), A240, A276, A479, A480, A798, A790,A815, A928, A988 SAE J405 |
Applications of Duplex Stainless Steel ASTM Grades
| Forging Specification | Common Designation | ASTM Cast | Wrought Bar Specification | Service Recommendations |
| ASTM A182 F44 | Super Stainless Steel (20% Chrome; 18% Nickel; 6% Mo; 0.25% C) | ASTM A351 Grade CK3MCuN (A995-1B) | ASTM A479 S31254 (2.54 SMO) | Used in acetic acid, antibiotics, drugs, bleaching compounds, formic acid, fruit juices, hot air, hot water, hydrocarbons, hydrochloric acid, organic liquids & acids, nitric acid, oxalic acid, phosphoric acid, seawater, sewage, sodium bisulfite, steam, sulfamic acid, 10% sulfuric acid. |
| ASTM A182 F50 | Super Stainless Steel (25.5% Chrome; 5.5% Nickel; 2% Mo; 0.040% C) | ASTM A995 Grade CD4MCuN | ASTM A479 S32550 | Applications in concentrated brine, fatty acids, potable water, pulp water, pulp liquors (220ºF / 104ºC), seawater, steam, sulfuric acid (15-30% @ 140-160ºF / 60-71ºC), sulfuric acid (35-40% @ 185ºF / 85ºC), and organics. |
| ASTM A182 F51 | Duplex Stainless Steel (22% Chrome; 5% Nickel; 3% Mo; N; 0.030% C) | ASTM A995 Grade CD3MN (4A) | ASTM A479 S31803 | Used in concentrated brine, fatty acids, potable water, pulp water, pulp liquors (220ºF / 104ºC), seawater, steam, sulfuric acid (15-30% @ 140-160ºF / 60-71ºC), sulfuric acid (35-40% @ 185ºF / 85ºC), and organics. |
| ASTM A182 F53 | Super Duplex Stainless Steel (25% Chrome; 7% Nickel; 4.5% Mo; N; 0.030% C) | ASTM A995 Grade CE3MN (5A) | ASTM A479 32750 | Suitable for concentrated brine, fatty acids, potable water, pulp water, pulp liquors (220ºF / 104ºC), seawater, steam, sulfuric acid (15-30% @ 140-160ºF / 60-71ºC), sulfuric acid (35-40% @ 185ºF / 85ºC), and organics. This grade is essential where a high Pitting Resistance Number (PREN) is required. |
| ASTM A182 F55 | Super Duplex Stainless Steel (25% Chrome; 7.5% Nickel; 3.5% Mo; N; 0.030% C) | ASTM A995 Grade CD3MWCuN (6A) | ASTM A479 32760 | Applications in concentrated brine, fatty acids, potable water, pulp water, pulp liquors (220ºF / 104ºC), seawater, steam, sulfuric acid (15-30% @ 140-160ºF / 60-71ºC), sulfuric acid (35-40% @ 185ºF / 85ºC), and organics. Like F53, it’s critical where the Pitting Resistance Number (PREN) is essential. |
Contact Us for Duplex Stainless Steel ASTM Grades
Looking for premium ASTM Grades of duplex stainless steel? ASTM A182 F51, F53, F55 & F61 are among the many duplex stainless steel products that Kalpataru Piping Solutions offers. Our materials provide exceptional strength, durability & corrosion resistance, making them ideal for applications in the oil and gas, aquatic, chemical processing, and desalination industries. Get premium duplex stainless steel items from a reliable manufacturer by raising inquiries regarding the product right away.
Frequently Asked Questions on Duplex Stainless Steel ASTM Grades
What is ASTM A182 F51?
The duplex stainless steel ASTM A182 F51 has a high mechanical strength, good weldability & a strong resistance to general, pitting, stress & crevice corrosion.
What is the yield of ASTM A182 F51?
The ASTM A182 F51 flange consists of duplex steel. The mechanical microstructure of the material demonstrates both ferritic & austenitic properties. Their minimum yield strength is 450 MPa & their tensile strength is 620 MPa.
What is ASTM A182 F53?
ASTM A182 F53 is equivalent to UNS S32750 which offers good resistance to pitting corrosion due to its higher chromium concentration as compared to F51.
What is the difference between ASTM A182 F53 and F55?
ASTM A182 F53 & F55 are different from each other due to chemical composition. The stainless steel ASTM A182 F53 has a chromium content of 14, 3 molybdenum content & nickel content of 2. ASTM A182 F55 is a stainless steel with 3 nickel, 4 molybdenum & 12 chromium.
What is ASTM A182 F55?
For applications demanding high temperature, bare forgings or forged & machined products are manufactured using ASTM A182 F55, a forging material specification for 55 grade stainless steel.
