ASTM A790 S32750

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ASTM A 790 Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe

This specification covers seamless and straight-seam welded ferritic/austenitic steel pipe intended for general corrosive service, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.

UNS number: S32205 (Ferritic/Austenitic steel)

Heat Treatment

Temperature: 1025-1125 °C

Quench: rapid cooling in air or water

Chemical requirements, %,

C: ≤0.030

Mn: ≤1.20

P: ≤0.035

S: ≤0.020

Si: ≤0.80

Cr: 24.0-26.0

Ni: 6.0-8.0

Mo: 3.0-5.0

N: 0.24-0.32

Cu: ≤0.50

Tensile requirements

Tensile Strength: ≥800MPa

Yield Strength.: ≥550MPa

Elongation in 2 in. or 50 mm, %: ≥15

Hardness:

HBW: ≤300

HRC: ≤32

Each tube shall be subjected to the nondestructive electric test or the hydrostatic test.

Permissible Variations in Wall Thickness

The minimum wall thickness at any point shall not be more than 12.5 % under the nominal wall thickness specified.

Permissible Variations in Outside Diameter

NPSOver, mmUnder, mm
1⁄8 –1 12, incl0.40.8
Over 11⁄2 to 4, incl0.80.8
Over 4 to 8, incl1.60.8
Over 8 to 18, incl2.40.8
Over 18 to 26, incl3.20.8
Over 26 to 34, incl4.00.8
Over 34 o 48, incl4.80.8