DUPLEX STEEL VALVES (F51/S31803/2205/CD3MN)

Duplex stainless is a mixed microstructure of austenitic and ferrite (50/50) which has improved strength over ferritic and austenitic steel grades with similar corrosion resistance qualities.

Global Supply Line offers valves ex stock and on an indent basis in duplex stainless steel materials such as forged ASTM A182-F51 cast A351-CD3MN and ASTM A351 CE8MN/CD4MCuN. Other grades are exotic and special stainless steels such as Super Duplex forged A182 F53 and A182 F55 (Zeron 100) and it’s cast equivalent A995 Grade 6A (CD3MWCuN) and A182 F44 and it’s equivalent A351 CK3MCuN are available upon request. Duplex A182-F51 is equivalent to:- UNS31803† and DIN 1.4462 and it is similar to:- 329LN, SAF2205, Uranus 45N.

Benefits of using Duplex Stainless Steel

  • Similar corrosion resistance to Type 316
  • Greater tensile and yield strength
  • Good ductility and toughness
  • Good stress corrosion cracking resistance (SSC)

Duplex stainless steel is designed to combine improved resistance to stress corrosion cracking (including sulfide stress corrosion cracking), pitting, crevice corrosion and high strength when compared with other stainless alloys. This alloy resists chloride environments and sulfide stress corrosion. It is also roughly double the strength of standard austentic stainless steels.

Applications

  • Petrochemical
  • Desalination plants
  • Chemical processing and transportation
  • Chloride-handling industries
  • Valve stems

Equivalent Grades

*S31803 has been supplemented by S32205 which has a higher minimum N, CR and Mo
A995 optionally supersedes A990 (1A and 1C are not referenced in A995) ASME B16.34 now only references A995. A890 is no longer used for pressure retaining castings.

ASTM GRADE A990-1A* A990/A995-1B A990-1C* A990/A995-2A A990/A995-3A A990/A995-4A A990/A995-5A A990/A995-6A A990/A995-7A
Type 25Cr5NiMoCu 25Cr5Ni2Mo3Cu 25Cr6NiMoCuN 24Cr10Ni4MoV 25Cr5NiMoV 22Cr5Ni3MoN 25Cr7Ni4MoN 25Cr7Ni3.5MoWCb 27Cr7Ni-Mo-W-N 25Cr7Ni3.5MoWCb
UNS No. J93370 J93372 J93373 J93345 J93371 S31803/S32205 S32750 S32760 S31254
ASTM No. A995-CD4MCuN A995 CD4MCu A351-CD3MCuN* A351-CE8MN/ CD3MCuN A351-CD6MN A995 CD3MN A351-CE3MN A995 CD3MWCuN A351-CD3MWN A351-CK3MCuN
Forged Equiv. A182-F50* F61* A182-F51 A182-F53 A182-F55 (Zeron 100TM) A182-F44
Common Name Duplex Duplex Duplex Duplex Duplex Duplex 2205 Super Duplex 32750 Super Duplex Super Austenitic/Duplex Super Duplex
European (DIN) 1.4462 1.4410 1.4501 UNS J93379

S31803 has been supplemented by S32205 (F60) which dual conforms to S31803 but has a higher minimum N, MO, NI and Cr which guarantees a better corrosion resistance.
*A9901A and 1C is not referenced in A995.
CD3MN, CD4MCu, CD3MWCuN have been deleted from A351 and added to A995 and may be supplied in compliance with grades 4A, 1B and 6A respectively.

Applications

FORGING SPECIFICATION COMMON DESIGNATION ASTM CAST WROUGHT BAR SPECIFICATION SERVICE RECOMMENDATIONS (1)
ASTM A182 F44 20% Chrome; 18% Nickel; 6% Mo; 0.25% C Super Stainless Steel ASTM A351 Grade CK3MCuN (A995-1B) Super Austenitic ASTM A479 S31254 (2.54 SMO) Acetic acid, antibiotics and drugs, bleaching compounds, formic acid, fruit and juices, hot air, hot water, hydrocarbons, hydrochloric acid, organic liquids and acids, nitric acid, organic salts, oxalic acid, phosphoric acid, sea water, sewage, sodium bisulfite, steam, sulfamic acid, 10% sulfuric acid.
ASTM A182 F50 25.5% Chrome; 5.5% Nickel; 2% Mo; 0.040% C Super Stainless Steel ASTM A351 Grade CD4MCu (A995-1A) ASTM A479 S32550 Concentrate brine, fatty acids, potable water, pulp water, pulp liquors at 220ºF (104ºC), sea water, steam, sulfuric acid (15-30% @ 140-160ºF (60-71ºC), sulfuric acid (35-40% @ 185ºF (85ºC), plus 5% organics).
24% Chrome; 9.5% Nickel; 4% Mo; 0.080% C Duplex Stainless Steel ASTM A351 Grade CE8MN (A995-2A) Concentrate brine, fatty acids, potable water, pulp water, pulp liquors at 220ºF (104ºC), sea water, steam, sulfuric acid (15-30% @ 140-160ºF (60-71ºC), sulfuric acid (35-40% @ 185ºF (85ºC), plus 5% organics).
ASTM A182 F51 22% Chrome; 5% Nickel; 3% Mo; N; 0.030% C Duplex Stainless Steel ASTM A351 Grade CD3MN (A995-4A) ASTM A479 S31803** Concentrate brine, fatty acids, potable water, pulp water, pulp liquors at 220ºF (104ºC), sea water, steam, sulfuric acid (15-30% @ 140-160ºF (60-71ºC), sulfuric acid (35-40% @ 185ºF (85ºC), plus 5% organics).
ASTM A182 F53 25% Chrome; 7% Nickel; 4.5% Mo; N; 0.030% C Duplex Stainless Steel Grade 5A ASTM A995 Grade CE3MN (A995-5A) Concentrate brine, fatty acids, potable water, pulp water, pulp liquors at 220ºF (104ºC), sea water, steam, sulfuric acid (15-30% @ 140-160ºF (60-71ºC), sulfuric acid (35-40% @ 185ºF (85ºC), plus 5%organics). Useful where the Pitting Resistance Number (PREN) is required.
ASTM A182 F55 25% Chrome; 7.5% Nickel; 3.5% Mo; N; 0.030%} C Duplex Stainless Steel Grade 6A ASTM A995 Grade CD3MWCuN (A995-6A) Concentrate brine, fatty acids, potable water, pulp water, pulp liquors at 220ºF (104ºC), sea water, steam, sulfuric acid (15-30% @ 140-160ºF (60-71ºC), sulfuric acid (35-40% @ 185ºF (85ºC), plus 5% organics). Useful where the Pitting Resistance Number (PREN) is required.

* No longer referenced in ASME

** S31803 has been supplemented by S32205 (F60) which has a higher minimum Ni Cr and Mo. (32205 Dual conforms to 31803)

Also see alternate Duplex Cross Reference, click here.

Applicable Standards

As well as ASTM A182 and A351 other standards such as ASTM A240, A789 and A790 also cover Duplex grades of valve bodies and trim materials.

Trade Name UNS Industry Specifications
SAF 2205 UNS S31803* ASME SA-182 (F51), SA-240, SA-798, SA-790, SA-815
ASTM A240, A276, A479, A789, A790, A815, A923, A928, A988
SAE J405
SAF 2205 UNS S32205* ASTM A240, A240M, A276, A479, A480, A480M, A798, A7901, A815, A923, A928, A988
SAE J40

* UNS31803 has been supplemented by S32205 (F60) which dual conforms to S31803 but has a higher minimum N, MO, NI and Cr which guarantees a better corrosion resistance.

General Duplex Stainless Steel Information

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 (A182 F51) composition has been refined over many years, and the resulting composition range was endorsed as UNS S32205 in 1996. Duplex S32205 provides excellent guaranteed corrosion resistance, but it should be noted much of the Duplex S31803 currently produced also dual conforms with Duplex S32205. 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.

Metallurgical Chemical Composition

UNS S31803/A182 F51/1.4462
C Cr Mn Mo N Ni P S Si
0.030 21.0- 2.00 2.50- 0.08- 4.50- 0.030 0.020 1.00
max 23.0 max 3.50 0.20 6.50 max max max

Correct as per ASTM A182/A182M-13. Based on A182 F51 (S31803 dual conforms)

UNS S32205
C Cr Mn Mo N Ni P S Si
0.030 22.0- 2.00 3.00- 0.14- 4.50- 0.030 0.020 1.00
max 23.0 max 3.50 0.20 6.50 max max max

Metallurgical Mechanical Properties A182 F51

Yield Strength Tensile Strength Elongation Reduction of Area Charpy Impact @Rt J Hardness H B
(Min) 50mm
>450Mpa (65KS I) >620Mpa (90KSI) 25% 45% 100* 270HB* Max

Correct as per ASTM A182/A182M-13. (UNS31803 is similar but slightly different)

PREn = Pitting Resistance Equivalent
PREn = Cr% + 3.3Mo% + 16N%

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