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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 Factory in China - Reliable Suppliers for Fast Delivery and Immediate Shipment

ZONSUN STEEL is a leading supplier and factory specializing in S31803 Duplex Stainless Steel Pipes, adhering to international standards. Based in China, we offer a comprehensive stock ready for immediate shipment, ensuring fast delivery to meet your needs. Trust us for high-quality products and reliable service as your preferred source for Duplex Stainless Steel solutions

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) (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 benefits of ASTM A790 S31803 duplex stainless steel pipes?

ASTM A790 S31803 duplex pipes combine austenitic and ferritic microstructures to deliver twice the yield strength of standard austenitic steels like 316L. They offer outstanding resistance to chloride-induced stress corrosion cracking (SCC), pitting, and crevice corrosion, making them highly cost-effective for harsh environments.

What are the typical applications for S31803 duplex steel pipes?

Common applications include oil and gas pipelines (especially for sour service), chemical and petrochemical processing systems, desalination and water treatment plants, marine/offshore structures, flue gas desulfurization in power plants, and heat exchangers.

What is the operating temperature range for S31803 duplex stainless steel?

S31803 duplex stainless steel performs reliably at temperatures ranging from -50°C up to 300°C (-58°F to 572°F), making it highly suitable for subsea operations and high-pressure systems.

What equivalent international grades correspond to S31803?

Equivalent grades include ISO X2CrNiMoN22-5-3, EN 1.4462, DIN X2CrNiMoN22-5-3, JIS SUS 329J3L, GB 022Cr22Ni5Mo3N, and the commercial name Duplex 2205.

What quality inspections and certifications are provided for these pipes?

Standard quality assurances include 100% PMI testing, EN 10204 3.1/3.2 Mill Test Certificates, Ultrasonic Testing (UT) / Eddy Current Testing (ECT), and mechanical testing (hardness, tensile, and impact tests) as per ASTM standards. Third-party inspections from organizations like SGS, BV, and TUV are also accepted.