Stainless Steel Pipe Fittings

1.4362 UNS 32304 Duplex Stainless Steel 2304 By

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1.4362 UNS 32304 Duplex Stainless Steel 2304 By

Duplex Stainless Steel 2304 UNS S32304 is a 23% chromium, 4% nickel, molybdenum-free duplex stainless steel. The Alloy 2304 has corrosion resistance properties similar to 316L. Furthermore, its mechanical properties, i.e., yield strength, are twice those of304L/316L austenitic grades. This allows the designer to save weight, particularly for properly designed pressure vessel applications.

Duplex Stainless Steel 2304 UNS S32304, is a lean duplex steel, similar to other duplex steels with it’s high strength and resistance to chlorides stress corrosion cracking, however, due to its lower alloying content it has a lower level of pitting and crevice corrosion resistance (PREN approximately 26). As it contains very little Molybdenum, 2304 is a good economical alternative to 316L in some applications although 2304 is not recommended for use above 300°C. Also known by the the Uranus 35N and SAF2304.

The Duplex Stainless Steel 2304 UNS S32304 is particularly suitable for applications covering the -50°C/+300°C (-58°F/572°F) temperature range. Lower temperatures may also be considered, but need some restrictions, particularly for welded structures. With its duplex microstructure, low nickel and high chromium contents, the alloy has improved stress corrosion resistance properties compared to 304 and 316 austenitic grades.

With its duplex microstructure and low nickel and high chromium contents, the alloy has improved stress corrosion resistance properties compared to 304 and 316 austenitic grades. uplex stainless steel 2304 successfully passes most of the standard IC test procedures such as ASTM, A262E, and C tests. Its corrosion rate in boiling nitric acid (65%) is higher than that of Alloy 316L. Due to its high yield strength, the alloy performs well in abrasion/corrosion applications.

Generally where 304 and 316L are used 
Pulp and paper industry (chip storage tanks, white and black liquor tanks, digestors) 
Caustic solutions, organic acids (SCC resistance) 
Food industry 
Pressure vessels (weight savings) 

Mining (abrasion/corrosion)

UNS 32304 Seamless Duplex Stainless Steel Pipe

ASTM/ASME………. A240 – UNS S32304
EURONORM………..1.4362 – X2 Cr Ni 23.4
AFNOR……………….Z3 CN 23.04 Az
DIN…………………….W. Nr 1.4362 
Corrosion Resistance
General Corrosion
Because of its high chromium content (23%) the corrosion resistance properties of 2304 are almost equivalent to those of 316L.
Localized Corrosion Resistance
The 23% chromium and 0.1% nitrogen additions explain why 2304 duplex stainless steel behaves much better than Alloy 316L when considering pitting and crevice corrosion resistance.
Stress Corrosion Resistance
Stress corrosion resistance test results in chloride containing aqueous solutions ((8ppm 02) PH =7, >1000 h, applied stresses higher than the yield strength) show that Alloy 2304 outperforms Alloys 304L and 316L, due to its high chromium additions and low nickel contents.This is a typical feature of duplex stainless steels. Alloy 2205 performs still better than 2304 in similar conditions.

Duplex Stainless Steel 1.4362 Composition % according to EN-10216-5:

C Si Mn P S Cr Mo Ni N Cu
max. 0,03 max. 1,00 max. 2,00 max. 0,035 max. 0,015 22,00 – 24,00 0,10 – 0,60 3,50 – 5,50 0,05-0,20 0,10-0,60

Duplex Stainless Steel S32304 Composition % according to ASTM A789,ASTM A790:

C Si Mn P S Cr Mo Ni N Cu
max. 0,03 max. 1,00 max. 250 max. 0,040 max. 0,040 21,50 – 24,50 0,50 – 0,60 3,00 – 5,50 0,05-0,20 0,50-0,60

Solution annealing : 950 – 1050 °C (water) 
Density 7800kg/m3 
Hardness Brinell 290 Max 
Tensile Strength @ Break 600 Mpa / 87000psi Min 
Tensile Strength @ Yield 400 Mpa / 58000 psi 0.2% offsett 
Elongation in 2″ 25% Min 
Modulus of Elasticity in tension 200Gpa 28500 ksi

Product Information for UNS 32304 Seamless Duplex Stainless Steel Pipe and tubing

Sizes Standard Tolerances
Products OD Wall Lengths and/or coils Grades OD Wall Lengths
Welded Heat Exchangers &Condensers

Specifications:ASTM-A789 and ASME-SA789

0.5″ (12.7 mm) to 4″ (101.6 mm)

Metric sizes available

0.020″ (0.51 mm) to 0.150″ (3.81 mm) Cut lengths to 60′ (18.3 m) LeanDuplex2304
<0.50″ (12.7 mm) 
+/-0.005″ (0.13 mm)
0.50″ (12.7 mm) to <1.50″ (38.1 mm) 
+/-0.005″ (0.13 mm)
1.50″ (38.1 mm) to <3.50″ (88.9 mm) 
+/-0.010″ (0.25 mm)
>3.50″ (88.9 mm) to 4.00″ (101.6 mm) 
+/-0.015″ (0.38 mm)
+/-15% +/-10% +1/8″ 
(3 mm)

Physical Properties of Duplex Stainless Steel 2304 in the Annealed Condition at -20°F to +100°F

      Tensile Strength Yield Strength            
Alloy UNS Spec. psi MPa ksi psi MPa ksi Elongation in 2 in. (min.) % Grain Size Req. Max.Hardness Modulus of Elasticity (x106 psi) Mean Coefficient of Thermal Expansion (IN./IN./°F x 10-6) Thermal Conductivity (BTU-in/ ft2-h-°F)
Lean Duplex 2304

OD=1″ & under

S32304 A789, A790 100,000 690 100* 65,000 450 58* 25 28 Rc, 30* Rc 27.5 7.6 180
Lean Duplex 2304


S32304 A789, A790 87,000 600 101* 58,000 400 58* 25 28 Rc, 30* Rc 27.5 7.6 180

*OD over 1.0″TS>87, YS>58, no hardness requirement 1.0″ OD and under

Duplex Stainless Steel 2304 Product Range

UNS Designation
Werkstoff NR.
Lean Duplex 2304
A/SA789, A/SA790

*Note: The specifications noted including ASTM, ASME, or other applicable authorities are correct at the time of publication. Other specifications may apply for use of these materials in different applications

Source: Zhejiang Yaang Pipe Industry Co., Limited (

Article Categories:
Duplex Stainless Steel

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