Duplex steel valve

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 A995 Grade 4A (formerly 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 and it’s cast equivalent A995 Grade 6A (formerly CD3MWCuN). 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 GRADEA990-1A*A990*/A995-1BA990-1C*A990*/A995-2AA990*/A995-3AA990*/A995-4AA990*/A995-5AA990*/A995-6AA990*/A995-7A
    Type25Cr5NiMoCu25Cr5Ni2Mo3Cu25Cr6NiMoCuN24Cr10Ni4MoV25Cr5NiMoV22Cr5Ni3MoN25Cr7Ni4MoN25Cr7Ni3.5MoWCb27Cr7Ni-Mo-W-N25Cr7Ni3.5MoWCb
    UNS No.J93370J93372J93373J93345J93371S31803/S32205†S32750S32760
    		S31254
    ASTM No.A995-CD4MCuNA995 ① CD4MCuA351-CD3MCuN*A351-CE8MN/ CD3MCuNA351-CD6MNA995 ① CD3MNA351-CE3MNA995 ① CD3MWCuNA351-CD3MWNA351-CK3MCuN
    Forged Equiv.A182-F50*
    		F61*

    		A182-F51A182-F53A182-F55(Zeron 100TM)A182-F44
    Common NameDuplexDuplexDuplexDuplexDuplexDuplex 2205Super Duplex 32750Super DuplexSuper Austenitic/DuplexSuper Duplex
    European (DIN)




    		1.44621.44101.4501UNS 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.

    *A990 1A and 1C is not referenced in A995. A990 is superceded by A995.

    ① 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 SPECIFICATIONCOMMON DESIGNATIONASTM CASTWROUGHT BAR SPECIFICATIONSERVICE RECOMMENDATIONS (1)
    ASTM A182 F4420% Chrome; 18% Nickel; 6% Mo; 0.25% C Super Stainless SteelASTM A351 Grade CK3MCuN (A995-1B) Super AusteniticASTM 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 F5025.5% Chrome; 5.5% Nickel; 2% Mo; 0.040% C Super Stainless SteelASTM A995 Grade CD4MCuNASTM A479 S32550Concentrate 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 SteelASTM A995 Grade CE8MN (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 F5122% Chrome; 5% Nickel; 3% Mo; N; 0.030% C Duplex Stainless SteelASTM A995 Grade CD3MN (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 F5325% Chrome; 7% Nickel; 4.5% Mo; N; 0.030% C Super Duplex Stainless Steel Grade 5AASTM A995 Grade CE3MN (5A)ASTM A479 32750Concentrate 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 F5525% Chrome; 7.5% Nickel; 3.5% Mo; N; 0.030%} C Super Duplex Stainless Steel Grade 6AASTM A995 Grade CD3MWCuN (6A)ASTM A479 32760Concentrate 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 NameUNSIndustry Specifications
    SAF 2205UNS 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 2205UNS 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
    CCrMnMoNNiPSSi
    0.03021.0-2.002.50-0.08-4.50-0.0300.0201.00
    max23.0max3.500.206.50maxmaxmax

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


    UNS S32205
    CCrMnMoNNiPSSi
    0.03022.0-2.003.00-0.14-4.50-0.0300.0201.00
    max23.0max3.500.206.50maxmaxmax

    METALLURGICAL MECHANICAL PROPERTIES A182 F51

    Yield StrengthTensile StrengthElongationReduction of AreaCharpy Impact @Rt JHardness 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%