ASTM A789 UNS S31803 Duplex Stainless Steel Heat Exchangers Tube

What is ASTM A789 UNS S31803 pipe?
ASTM A789/A789M covers nominal wall thickness grades suitable for applications requiring general corrosion resistance, with particular emphasis on stress corrosion cracking. These steels are susceptible to embrittlement when subjected to prolonged use at high temperatures.

ASTM A789 S31803 seamless pipe meets the material specification for duplex steel (an alloy with the addition of chromium and molybdenum). UNS S31803 is a widely used duplex stainless steel alloy pipe material. Composed of medium carbon steel (50% ferrite and 50% austenite), it offers excellent mechanical properties and weldability.

SA789 S31803 bright annealed pipe offers excellent resistance to chloride stress corrosion cracking and is widely used in marine, food processing, automotive, and various other industries. It is also very strong and can be used in high-pressure applications.

 

ASTM A789 /A789M Stainless tubes shall be made by the seamless or welded process with no filler metal added.

Standard: ASTM A789/A789M, ASME SA789
Seamless pipe & Tube Size: 1/2" to 8"
Welded pipe & Tube Size: 6" to 24"
Outer Diameter: 6.0-630mm
Schedules: 10s, 20, 40s, 40, 60, 80s, 80, 100, 120, 140, 160, XXH
Wall Thickness: 1mm to 50mm

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Chemical composition for ASTM A789 UNS S31803 tubing, %

C	≤0.030
Mn	≤2.00
P	≤0.030
S	≤0.020
Si	≤1.00
Ni	4.5-6.5
Cr	21.0-23.0
Mo	2.5-3.5
N	0.08-0.20

Physical Properties of A789 UNS S31803 welded tube

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Co-eff of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C ( J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100°C	0-315°C	0-538°C	at 100°C	at 500°C
UNS S32205 / 2205	782	190	13.7	14.2	-	19	-	418	850

 

Mechanical Composition of ASTM A789 UNS S31803 heat exchanger tubes

Grade	Tensile Strength (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min	Hardness
				Rockwell C (HR C)	Brinell (HB)
UNS S32205 / 2205	621	448	25	31 max	293 max

 

A789 UNS S31803 Heat Exchanger Tubes Temperature Range

Product	Temperature Range
UNS S31803 Tubing	Up to 600°F (316°C)

 

A789 S31803 Heat Exchanger Tubes Testings

Reverse Flattening Test

Flaring Test

Flange Test

Nondestructive Testing

Moisture testing

PMI Test

 

Markings

Marking prescribed in specification A450/A 450M, The marking shall indicate whether the tubing is seamless or welded.

 

Note:

Mill test certificates will be issued according to EN10204.3

All tubes shall be supplied as per applicable ASTM A789 /A789M Specification.

 

Packing and Marking

Packed in bundles or ply wooden box wrapped in plastic, and suitably protected for sea-worthily delivery or as requested.