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904L/N08904 GRADE SS SMLS PIPE

S31803 GRADE Duplex SS SMLS PIPE

S32205 GRADE Duplex SS SMLS PIPE

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S31803 Duplex Stainless Steel Pipes from China Factory - Reliable Suppliers for Immediate Shipment

ZONSUN STEEL is a leading supplier and exporter of S31803 Duplex Stainless Steel Pipes, manufactured in our state-of-the-art factory in China. Our products are compliant with international standards, ensuring high quality and reliability. We have a large stock available for immediate shipment, allowing for fast delivery to meet your urgent needs. Choose ZONSUN STEEL for all your Duplex Stainless Steel requirements and experience exceptional service from trusted suppliers in the industry

Product Detail

Introduction

ASTM A790/A790M S31803 duplex stainless steel pipes combine austenitic and ferritic microstructures, delivering twice the strength of 316L with exceptional resistance to chloride-induced stress corrosion cracking (SCC). Ideal for harsh offshore, chemical, and marine applications, this alloy balances cost-efficiency with premium performance.

Key Features

Dual-Phase Strength

Yield strength ≥450 MPa, nearly double conventional stainless steels (e.g., 304/316), reducing wall thickness and material costs.

Enhanced Corrosion Resistance

21%-23% Cr, 2.5%-3.5% Mo, and 4.5%-6.5% Ni combat pitting/crevice corrosion in seawater, acids, and sour gas (H₂S) environments (PREN ≥35).

Thermal Stability

Performs reliably from -50°C to 300°C (-58°F to 572°F), suitable for subsea and high-pressure systems.

Material Specification

Standard

ASTM A790/A790M

O.D

1/8" NB TO 32" NB, (10.29MM-812.80MM), (Customization Available)

W.T

SCH 10S, SCH 40S, SCH 80S, SCH160, SCH XXS (Customization Available)

Application

Oil & Gas Pipelines (Including Sour Service)
Chemical & Petrochemical Processing
Desalination & Water Treatment Plants
Marine & Offshore Structures
Power Plants (Including Flue Gas Desulfurization)
Pulp & Paper Industry
Heat Exchangers & Condensers

End

Plain End, Beveled End, Threaded

Processing

Cut-to-length; Polishing.

Inspection

100% PMI (Positive Material Identification) Tested
EN 10204 3.1/3.2 Mill Test Certificate
Third-Party Inspection Accepted (SGS, BV, TUV, etc.)
Ultrasonic Testing (UT) / Eddy Current Testing (ECT) Available
Hardness, Tensile, and Impact Testing as per ASTM Standards

Delivery Condition

Cold Drawn, Annealed and Pickled / Polished / Bright Annealed / Sand blasting / Shot Blasting.

Marking

All SS SMLS Pipes are marked as follows: Standard, Grade, OD, Thickness, Length, Heat No. (Or as per the customer’s request)

Packing

Packed in Wooden Boxes, plywood cases, Steel Strips Bundled, or as per Customers Requests

Specials

Sizes and Specifications other than above can be customized on request.

Specification Parameters

S31803 Chemical Composition

HEAT NO.		CHEMICAL COMPOSITION (%)
HEAT NO.		C	Mn	P	S	Si	Ni	Cr	Mo	N
STAND.	MIN.	-	-	-	-	-	4.50	21.00	2.50	0.08
STAND.	MAX.	0.03	2.00	0.03	0.020	1.00	6.50	23.00	3.50	0.20

S31803 Mechanical Properties

Mechanical Properties
Grade	Tensile Strength (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min	Hardness (HRW)	Hardness (HRC)
S31803	620	450	25	290	30

Equivalent Grades (ASTM A790/A790M S31803 Equivalent Grades)

ASTM A790/A790M S31803 (UNS S31803) Equivalent Grades
ISO	EN (Europe)	DIN (Germany)	JIS (Japan)	GB (China)	UNS (USA)	AISI/SAE
X2CrNiMoN22-5-3 (ISO 15510)	1.4462 (EN 10088-2)	X2CrNiMoN22-5-3 (DIN 17440)	SUS 329J3L (JIS G3463)	022Cr22Ni5Mo3N (GB/T 21833)	S31803	Duplex 2205 (Commercial Name)

ASTM A312/A312M Standard Cold Machining Size Deviation Permitted

ASTM A312/A312M-09 Standard Permitted Tolerance of WT and OD
Nominal Outside Diameter		Allowable Deviation	Nominal Wall Thickness		Allowable Deviation
1/8”—1 1/2“	(10.29—48.26)	+0.4 -0.8	1/8”—1 1/2“	(10.29-73.03) all of t	+20 -12.5
>1 1/2“—4”	(48.26—114.3)	±0.8	3“—18”	(88.9-457.2) t/D=5%	+22.5 -12.5
>4”—8"	(114.3—219.08)	+1.6 -0.8	3“—18”	(88.9-457.2) t/D>5%	+15 -12.5
>8“—18"	(219.08—457.2)	+2.4 -0.8	≥20"	=508 t of wld pipe	+17.5 -12.5
>18”—26“	(457.2—660.4)	+3.2 -0.8	≥20"	=508 t/D=5%	+22.5 -12.5
>26”—34”	(660.4—863.6)	+4.0 -0.8	≥20"	=508 t/D>5%	+15 -12.5
>34“—48"	(863.6—1219.2)	+4.8 -0.8	-	-	-
Thin wall pipe (t/D=3%) ovality condition: Any cross section in a steel pipe Dmax Dmin=1.5% nominal, and (Dmax Dmin)/ 2 conforms to the stipulated diameter tolerance range.

Comparison Table Of American Standard Dimensions (ANSI B36.19 & ANSI B36.10) (Refers to ASTM A312)

OD DN	IN	OD MM	ANSI B36.19										ANSI B36.10
			Nominal diameter in inches
			5s		10s		Sched.40s		Sched.40	Sched.80s		Sched.80	10		20		30		Standard
			mm	Kg/m	mm	Kg/m	mm	Kg/m	mm	mm	Kg/m	mm	mm	Kg/m	mm	Kg/m	mm	Kg/m	mm	Kg/m
6	1/8"	10.29	-	-	1.24	0.281	1.73	371	1.73	2.41	0.467	2.41	-	-	-	-	-	-	1.73	0.371
8	1/4"	13.72	-	-	1.65	0.499	2.24	0.644	2	3.02	0.809	3.02	-	-	-	-	-	-	2.24	0.644
10	3/8"	17.14	-	-	1.65	0.64	2.31	0.858	2.31	3.2	1.118	3.2	-	-	-	-	-	-	2.31	0.858
15	1/2"	21.34	1.65	0.814	2.11	1.016	2.77	1.26	2.77	3.73	1.62	3.73	-	-	-	-	-	-	2.77	1.26
20	3/4"	26.67	1.65	1.034	2.11	1.298	2.87	1.68	2.87	3.91	2.19	3.91	-	-	-	-	-	-	2.87	1.68
25	1"	33.4	1.65	1.312	2.77	2.125	3.38	2.5	3.38	4.55	3.23	4.55	-	-	-	-	-	-	3.36	2.5
32	1 1/4"	42.16	1.65	1.674	2.77	2.732	3.56	3.38	3.56	4.85	4.46	4.85	-	-	-	-	-	-	3.56	3.38
40	1 1/2"	48.26	1.65	1.926	2.77	3.155	3.68	4.05	3.68	5.08	5.4	5.08	-	-	-	-	-	-	3.68	4.05
50	2"	60.32	1.65	2.424	2.77	3.992	3.91	5.43	3.91	5.54	7.47	5.54	-	-	-	-	-	-	3.91	5.43
65	2 1/2"	73.02	2.11	3.747	3.05	5.345	5.16	8.62	5.16	7.01	11.4	7.01	-	-	-	-	-	-	5.16	8.62
80	3"	88.9	2.11	4.585	3.05	6.557	5.49	11.28	5.49	7.62	15.25	7.62	-	-	-	-	-	-	5.49	11.28
90	3 1/2"	101.6	2.11	5.272	3.05	7.526	5.74	13.56	5.74	8.08	18.62	8.08	-	-	-	-	-	-	5.74	13.56
100	4"	114.3	2.11	5.945	3.05	8.496	6.02	16.06	6.02	8.56	22.29	8.56	-	-	-	-	-	-	6.02	16.06
125	5"	141.3	2.77	9.639	3.4	11.74	6.55	21.76	6.55	9.52	30.92	9.52	-	-	-	-	-	-	6.55	21.76
150	6"	168.28	2.77	11.514	3.4	14.037	7.11	28.23	7.11	10.97	42.52	10.97	-	-	-	-	-	-	7.11	28.23
200	8"	219.08	2.77	15.049	3.76	20.334	8.18	42.49	8.18	12.7	64.57	12.7	-	-	6.35	33.28	7.04	36.8	8.18	42.4
250	10"	273.05	3.4	23.028	4.19	28.29	9.27	60.24	9.27	12.7	81.46	15.09	-	-	6.35	41.7	7.8	51	9.27	60.24
300	12"	323.85	3.96	31.806	4.57	36.633	9.52	73.76	10.31	12.7	97.36	17.48	-	-	6.35	49.68	8.38	65.14	9.52	73.76
350	14"	355.6	3.98	34.99	4.78	42.102	9.52	-	11.13	-	-	19.05	6.35	54.63	7.92	67.98	9.52	81.21	9.52	81.21
400	16"	406.4	4.19	42.35	4.78	48.22	9.52	-	12.7	-	-	21.44	6.35	62.58	7.92	77.9	9.52	93.13	9.52	93.18
450	18"	457.2	4.19	47.7	4.78	54.3	9.52	-	14.27	-	-	23.82	6.35	70.5	7.92	87.8	11.13	122.12	9.52	105.05
500	20"	508	4.77	60.32	5.54	69.766	9.52	-	15.09	-	-	26.19	6.35	78.47	9.52	116.97	12.7	155	9.52	116.97
550	22"	558.8	4.77	-	5.54	-	9.52	-	-	-	-	28.58	6.35	86.42	9.52	128.89	12.7	170.86	9.52	128.89
600	24"	609.6	5.54	84.1	6.35	96.215	9.52	-	17.48	-	-	30.96	6.35	96.215	9.52	140.8	14.7	209.54	9.52	140.81
650	26"	660.4	-	-	-	-	9.52	-	-	-	-	-	7.92	127.58	12.7	202.65	-	-	9.52	152.73
700	28"	711.2	-	-	-	-	9.52	-	-	-	-	-	7.92	137.52	12.7	218.54	15.88	271.94	9.52	164.65
750	30"	762	6.35	120.59	7.92	147.45	9.52	-	-	-	-	-	7.92	147.45	12.7	234.44	15.88	291.81	9.52	176.57
800	32"	812	-	-	-	-	9.52	-	17.48	-	-	-	7.92	157.39	12.7	250.33	15.88	311.67	9.52	188.5
850	34"	863.6	-	-	-	-	9.52	-	17.48	-	-	-	7.92	167.32	12.7	266.22	15.88	331.54	9.52	200.42
900	36"	914.4	-	-	-	-	9.52	-	19.05	-	-	-	7.92	177.26	12.7	282.18	15.88	351.41	9.52	212.34

Frequently Asked Questions

What are the main advantages of ASTM A790 S31803 duplex stainless steel pipes?

They combine austenitic and ferritic microstructures, offering dual-phase strength (yield strength ≥450 MPa, nearly double that of 304/316) and exceptional resistance to chloride-induced stress corrosion cracking (SCC), pitting, and crevice corrosion.

What is the chemical composition of S31803 duplex steel?

According to the standard specifications, S31803 contains 21.00%-23.00% Chromium (Cr), 4.50%-6.50% Nickel (Ni), 2.50%-3.50% Molybdenum (Mo), 0.08%-0.20% Nitrogen (N), with maximum limits of 0.03% Carbon (C), 2.00% Manganese (Mn), and 1.00% Silicon (Si).

What are the mechanical property requirements for S31803?

S31803 steel has a minimum tensile strength of 620 MPa, a minimum yield strength (0.2% proof) of 450 MPa, and a minimum elongation of 25% (in 50mm). The maximum hardness values are 290 HRW and 30 HRC.

What equivalent grades correspond to UNS S31803?

Equivalent grades include X2CrNiMoN22-5-3 (ISO 15510 / DIN 17440), 1.4462 (EN 10088-2), SUS 329J3L (JIS G3463), 022Cr22Ni5Mo3N (GB/T 21833), and Duplex 2205 (commercial name).

In which industries and applications are S31803 pipes typically used?

They are widely used in Oil & Gas Pipelines (including sour service), Chemical & Petrochemical Processing, Desalination & Water Treatment Plants, Marine & Offshore Structures, Power Plants (including Flue Gas Desulfurization), Pulp & Paper Industry, and Heat Exchangers & Condensers.

What testing and inspections are available for these duplex stainless steel pipes?

Standard options include 100% PMI testing, EN 10204 3.1/3.2 Mill Test Certificates, third-party inspections (SGS, BV, TUV, etc.), Ultrasonic Testing (UT), Eddy Current Testing (ECT), as well as hardness, tensile, and impact testing according to ASTM standards.