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