Description
| Duplex Stainless Steel 2205, S31803, S32205, SUS329J3L, 1.4462, A182 F51 | |||
| What material is S31803?
Duplex 2205 is the most widely used duplex (ferritic/austenitic) stainless steel grade. It finds applications due to both excellent corrosion resistance and high strength. The standard duplex S31803 stainless steel composition has over the years been refined by many steel suppliers, and the resulting restricted composition range was endorsed as UNS S32205 in 1996. Duplex S32205 gives better guaranteed corrosion resistance, but for much of the Duplex S31803 currently produced also complies with Duplex S32205. Stainless steel 2205 is not generally suitable for use at temperatures above 300ºC as it suffers from precipitation of brittle micro constituents, nor below -50ºC because of its ductile-to-brittle-transition..It is used extensively by the Marine, Chemical, Petrochemical, Pulp and Paper, Oil and Gas, Transport and allied processing industries.Typical uses are: Anchor Guides, Conveyors, Fasteners, Bushings, High Strength Pump Shafts, Propellor Shafts, plus various applications currently using standard austenitic stainless steel grades. |
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| Duplex s31803 Related Specifications | |||
| German | W.Nr 1.4462, DIN X2CrNiMoN22 5 3 | ||
| USA | ASTM A276-98b, UNS S31803 , S32205 | ||
| s31803 Chemical Composition | Min. % | Max. % | |
| Carbon | 0 | 0.03 | |
| Silicon | 0 | 1.00 | |
| Manganese | 0 | 2.00 | |
| Nickel | 4.50 | 6.50 | |
| Chromium | 21.00 | 23.00 | |
| Molybdenum | 2.50 | 3.50 | |
| Nitrgogen | 0.08 | 0.20 | |
| Phosphorous | 0 | 0.03 | |
| Sulphur | 0 | 0.02 | |
| Mechanical Property Requirements – Annealed (As Supplied) to ASTM A276-98b UNS S31803 for Hot and Cold Finished | |||||||
| Tensile Strength Mpa (Min) |
0.2 % Yield Strength Mpa ( Min ) |
Elongation in 50mm % Min |
Hardness HB Max |
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| 620 | 448 | 25 | 290 | ||||
| Typical Mechanical Properties at room temperature – Annealed | |||||||
| Tensile Strength ( Mpa ) |
Yield Strength ( Mpa ) |
Elongation in 50mm ( % ) |
Charpy V Impact (J ) |
Hardness | |||
| HB | Rc | ||||||
| 650 – 900 | 570 | 30 | 130 | 235 | 23 | ||
| Elevated Temperature Properties* | |||||||
| While the oxidation resistance of 2205 is good at high temperature as with other duplex stainless steel grades, it is subject to embrittlement when exposed to temperatures above 300 oC even for short periods. It is subject to embrittlement at 475 oC when exposed for 2 hours only, also between 370 oC and 540 oC over a longer period.
Precipitation of sigma phase will also occur above 650 oC resulting in decreased ductility and corrosion resistance. Duplex 2205 is therefore not recommended for use at temperatures above 300 oC. |
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| Typical Mechanical Properties at Elevated Temperatures for 63.5 mm Dia Section – Annealed Condition | |||||||
| Test Temperature oC |
Tensile Strength Mpa |
Yield Strength Mpa |
Charpy V Notch Impact After 100 Hours at Temp. J |
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| 315 | 650 | 390 | 45 | ||||
| 370 | 640 | 375 | 22 | ||||
| 480 | 5 | ||||||
| N.B. Should embrittlement occur then annealing is required to rectify. | |||||||
| Low Temperature Properties | ||||||||||
| Duplex 2205 stainless steel is not recommended for use at temperatures below -50 oC, again due to its embrittling effect resulting in low ductility.
N.B. Unlike high temperature exposure however, the embrittling effect of low temperature exposure is not permanent, existing only for the duration at low temperature. |
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| Typical Charpy V-Notch Impact Properties at Low and Sub Zero Temperatures | ||||||||||
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| Corrosion Resistance | ||||||||||
| General Corrosion | ||||||||||
| S31803 has superior resistance to general corrosion in most media than ss316L or ss317L austenitic stainless steel grades | ||||||||||
| Stress Corrosion Cracking | ||||||||||
| S32205 has a much higher resistance to stress corrosion cracking than ss304L or ss316L austenitic stainless steel grades. | ||||||||||
| Pitting Corrosion | ||||||||||
| Duplex 2205 has a higher resistance to pitting corrosion than sus316L or sus317L austenitic stainless steel grades. | ||||||||||
| Crevice Corrosion / Erosion Corrosion | ||||||||||
| Duplex 2205 has a higher resistance to crevice corrosion and erosion corrosion than sus316L austenitic stainless steel grade. | ||||||||||
| Corrosion Fatigue | ||||||||||
| Duplex stainless steel 2205 has better fatigue strength in corrosive environments than the standard austenitic stainless steel grades due to its higher strength and higher corrosion resistance. | ||||||||||
| Heat Treatment | ||||||||||
| Annealing | ||||||||||
| Heat to 1020 oC – 1100 oC. Hold until temperature is uniform throughout the section. *Soak as required.
Quench in water to obtain optimum corrosion resistance. *Actual soaking time should be long enough to ensure that the part is heated thoroughly throughout its section to the required temperature, 30 minutes per 25mm of section may be used as a guide. |
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| Machining | ||||||||||
| The machinability of S31803 in the annealed as supplied condition is lower than either SUS 304 and SUS 316 due to it’s higher yield strength (approximately double).
Typically 80% as machinable as the standard SUS304 and SUS316 grades, but lower against the improved machinability SS304 and SS316 stainless steel. N.B. All machining should be carried out as per machine manufacturers recommendations for suitable tool type, feeds and speeds. |
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| Welding | ||||||||||
| Duplex 2205 is readily weldable by the various standard electric arc welding processes.
Oxcyacetylene welding is however not recommended due to the possibility of carbon pick up in the weld area. |
