S32205 Super Duplex SS Special Alloys For Petrochemical Industry CMMC Brand

Stainless steel Duplex 2205 (S32205) for oil and gas such as valve, fitting, shaft and pump part etc

1 PRODUCT

Duplex stainless steel Duplex 2205 (UNS S32205) for oil and gas production equipment such as valves, fittings, shafts and pump parts etc.

Duplex is available from us as round bar, flat bar, hexagonal bar, shaped bar, forging, forging block, plate, sheet, strip, wire, pipe and tubes, fasteners, bolts & nuts etc.

2 EQUIVALENT DESIGNATION

UNS S32205, UNS S31803, SAF 2205, W.Nr. 1.4462, 00Cr22Ni5Mo3N

3 OVERVIEW

Duplex 2205 is a nitrogen-enhanced duplex stainless steel. It possesses good resistance to general corrosion in many acid environments and, has excellent resistance to chloride stress corrosion cracking, pitting and crevice corrosion.

The nitrogen serves to significantly improve the corrosion resistance of the alloy; especially in the welded condition. Earlier duplex alloys have had moderate resistance to general corrosion and chloride stress corrosion cracking, but suffered a substantial loss of properties when used in the as-welded condition. To impart the metallurgical benefits of nitrogen to both improved corrosion performance and as-welded properties, Duplex 2205 is produced to a 0.15% minimum nitrogen content compared to the ASTM range of 0.08-0.20% for S31803 and 0.14-0.20% for S32205. The minimum Cr, Mo and Ni contents of Duplex 2205 (22.0, 3.1 and 5.5% respectively) satisfy the requirements of both the UNS S31803 and S32205 composition specifications. The typical high Cr, Mo and Ni contents of Duplex 2205 give it a high PREN (Pitting Resistance Equivalent) of 35.8, further enhancing its corrosion resistance. The PREN of Duplex 2205 exceeds those of types 316L and 317L stainless steels.

4 APPLICATION

Duplex 2205 has been used in high pressure fuel injector systems; oil and gas production equipment such as valves, fittings, shafts, and pump parts; heat exchangers in chemical and pulp and paper plants; and brewery tanks. It can be considered in situations where the strength and or corrosion resistance of Type 316 is inadequate.

5 CHEMICAL COMPOSITION

6 PHYSICAL PROPERTIES

Density at 72°F(22°C): 7.82 g/cm³ (0.283lb/in³)

Melting range: 1385-1440°C (2525-2625°F)

Thermal Conductivity at 212°F(100°C): 8.4BTU/hr·ft·°F(14.6W/m·K)

Poisson's Ratio: 0.300

Modulus of elasticity in tension at 72°F(22°C): 29.0 x 10³ ksi (200GPa)

Magnetic permeability: Ferromagnetic (In the annealed and hot rolled conditions)

7 METALLURGICAL STRUCTURE

Duplex 2205 has a microstructure consisting of austenite and ferrite phases. This duplex microstructure and the chemical composition of Duplex 2205 results in an excellent combination of strength and corrosion resistance.

When heat-treated properly, the composition of Duplex 2205 produces a microstructure that consists of a nearly equal mixture of austenite and ferrite phases as shown in the photomicrograph below. The microstructure and composition of the Duplex 2205 provide corrosion resistance to many environments that is superior to Types 316 or 317, and a minimum yield strength that is more than double that of conventional austenitic stainless steels.

8 MECHANICAL PROPERTIES

Typical mechanical properties for annealed Duplex 2205 material at room temperature are listed below

9 CORROSION RESISTANCE

Compared to conventional austenitic stainless steels such as Type 304 and 316, Duplex 2205 possesses superior resistance in most oxidizing and reducing acids; superior chloride pitting and crevice corrosion resistance due to higher chromium, molybdenum and nitrogen content; and superior resistance to chloride stress corrosion cracking.

Duplex 2205 has good intergranular corrosion in the as-annealed and as-weld conditions. Some intergranular attack may occur in the hot rolled unannealed condition.

For optimum corrosion resistance, surfaces must be free of scale, lubricants, foreign particles, and coatings applied for drawing and heading. After fabrication of parts, cleaning and/or passivation should be considered.

9 WORKING INSTRUCTION

Hot working

Heat uniformly to 2000/2100°F (1093/1149°C).Reheat as often as necessary. Cool forgings in air.

Cold working

Cold working increases strength and hardness. Work hardening rate is lower than Type 304, but the annealed strength of 2205 is significantly higher.

Machinability

Duplex 2205 has a machinability between conventional Type 316 and 22Cr-13Ni-5Mn stainless. The alloy machines with chip characteristics that are tough and stringy. Use of chip curlers and breakers is advised.

10 HEAT TREATMENT

Annealing

Heat to 1850/2050°F (1010/1121°C) and rapidly quench in water or air. Typical hardness as-annealed is HRC 23.

Annealing near 2010°F will increase the amount of ferrite present in the microstructure compared to that resulting from annealing near 1850°F.

Hardening

Cannot be hardened by heat treatment. Can be hardened only by cold working.

Stress relieving or deliberate slow cooling is not recommended due to possible embrittlement, which can result from exposure in the range of 650 - 1830˚F. ASTM test method A923/A (metallographic technique) or A923/C (corrosion test technique) are often employed to verify appropriate heat treatment.

11 COMPETITIVE ADVANTAGE

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Patented technologies.
(4) Excellent performance

12 STANDARD SPECIFICATION

NACE MR0175 / ISO 15156

Chemical composition: GB/T 20878

Seamess and welded tube and pipe: ASTM A270, ASTM A789 / ASME SA789, ASTM A790 / ASME SA790, ASTM A928

Pipe fitting: ASTM A815 / ASME SA815

Bar and rod: ASTM A182 / ASME SA182, ASTM A276 / ASME SA276, ASTM A479 / ASME SA479, BS 6744

Plate, sheet and strip: ASTM A240 / ASME SA240

13 BUSINESS TERM