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ASTM A 789 Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service
UNS number: S31803 (Ferritic/Austenitic steel)
Ordering Information
Orders for product under this specification should include the following, as required, to describe the desired material adequately:
1 Quantity (feet, metres, or number of lengths),
2 Name of product (seamless or welded tubes),
3 Grade ,
4 Size (outside diameter and average wall thickness, unless minimum wall thickness is specified),
5 Length (specific or random),
6 Optional requirements,
7 Test report required (see the Inspection section of Specification A1016/A1016M),
8 Specification designation, and
9 Special requirements.
Manufacture
The tubes shall be made by the seamless or welded process with no filler metal added.
Heat Treatment
Temperature: 1020-1100 °C
Quench: rapid cooling in air or water
Chemical requirements, %,
C: ≤0.030
Mn: ≤2.00
P: ≤0.030
S: ≤0.020
Si: ≤1.00
Cr: 21.0-23.0
Ni: 4.5-6.5
Mo: 2.5-3.5
N: 0.08-0.20
Tensile requirements
Tensile Strength: ≥620MPa
Yield Strength.: ≥450MPa
Elongation in 2 in. or 50 mm, %: ≥25
Hardness:
HBW: ≤290
HRC: ≤30
Each tube shall be subjected to the nondestructive electric test or the hydrostatic test.
Permissible Variations in Dimensions
Size, Outside Diameter, mm |
Permissible Variations in Outside Diameter, mm |
Average Wall Permissible Variations in Wall Thickness, % |
≤12.7 | 0.13 | ±15 |
12.7<D≤38.1 | 0.13 | ±10 |
38.1<D≤88.9 | 0.25 | ±10 |
88.9<D≤139.7 | 0.38 | ±10 |
139.7<D≤203.2 | 0.76 | ±10 |
Contact Person: Mr. Sam Cui
Tel: +86 130 3189 1590