ASTM A790/A790M-22 Standard
Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASTM A790 covers seamless and straight-seam welded ferritic/austenitic duplex stainless steel pipe for general corrosive service, with particular emphasis on resistance to stress corrosion cracking. The pipe shall be made by the seamless or an automatic welding process, with no addition of filler metal in the welding operation. Heat analysis shall be made to determine the percentages of the elements specified. Tension tests, hardening tests, flattening tests, hydrostatic test and nondestructive electric tests shall be made to conform to the specified requirements.
ASTM A790 Duplex Stainless Steel Pipe Grades
HT PIPE supplies a wide range of duplex and super duplex stainless steels, all of which are included in the ASTM A790 specification. These include:
- UNS S31803 (Duplex 2205, 1.4462, F51)
- UNS S32205 (Duplex 2205, 1.4462, F60)
- UNS S32750 (2507, 1.4410, F53)
- UNS S32760 (Zeron 100, 1.4501, F55)
- UNS S32550 (Ferralium 255, 1.4507, F61)
ASTM A790 Duplex Stainless Steel Pipe Specifications
| Standard | ASTM A790 | |
| Grade | S31803, S32205, S32750 | |
| Yield Strength (Mpa) | ≥450;≥450;≥550 | |
| Tensile Strength (Mpa) | ≥620;≥655;≥800 | |
| Elongation(%) | ≥25;≥25;≥15 | |
| Hydrostatic Test | The Hydrostatic Test shall be in accordance with ASTM A999. | |
| Could be replaced by ECT. | ||
| Intergranular Corrosion Test | Usually use Pitting Corrosion Test. | |
| Eddy Current Test | Could be replaced by HT. | |
| O.D. Tolerance (mm) | O.D. | O.D.Tolerance |
| 10.3≤D≤48.3 | -0.5 | |
| 48.3 | -1 | |
| 114.3 | -2 | |
| 219.1 | -3 | |
| W.T. Tolerance | O.D. | W.T.Tolerance |
| 10.3≤D≤73.0 | -1.6 | |
| 88.9≤D≤457.0 | -1.8 | |
| t/D ≤5% | ||
| 88.9≤D≤457.0 | -1.2 | |
| t/D >5% | ||
Tensile Strength and Hardness Requirements
| Grade | Tensile strength, min., ksi [MPa] | Yield strength, min., ksi [MPa] | Elongation in 2 in., or 50mm, min, % | Hardness, Max Brinell |
| S31803 | 90 [620] | 65 [450] | 25 | 290 |
| S32205 | 95 [655] | 70 [485] | 25 | 290 |
| S31500 | 92 [630] | 64 [440] | 30 | 290 |
| S32550 | 110 [760] | 80 [550] | 15 | 297 |
| S31200 | 100 [690] | 65 [450] | 25 | 280 |
| S31260 | 100 [690] | 65 [450] | 25 | 290 |
| S32001 | 90 [620] | 65 [450] | 25 | 290 |
| S32304 | 100 [690] | 65 [450] | 25 | 290 |
| S32750 | 116 [800] | 80 [550] | 15 | 310 |
| S32760 | 109 [750] | 80 [550] | 25 | 300 |
| S32950 | 100 [690] | 70 [480] | 20 | 290 |
| S32520 | 112 [770] | 80 [550] | 25 | 310 |
Heat Treatment
| UNS Designation | Temperature | Quench |
| S31803 | 1870-2010 °F [1020-1100°C] | Rapid cooling in air or water |
| S32205 | 1870-2010 °F [1020-1100°C] | Rapid cooling in air or water |
| S31500 | 1800-1900 °F [980-1040°C] | Rapid cooling in air or water |
| S32550 | 1900 °F [1040°C] min. | Rapid cooling in air or water |
| S31200 | 1920-2010 °F [1050-1100°C] | Rapid cooling in water |
| S31260 | 1870-2010 °F [1020-1100°C] | Rapid cooling in water |
| S32001 | 1800-1950 °F [982-1066°C] | Rapid cooling in air or water |
| S32003 | 1850-2050 °F [1010-1120°C] | Rapid cooling in air or water |
| S32101 | 1870 °F min | Quenched in water or Rapidly cooling in other means |
| S32202 | 1870-1975 °F [1020-1080°C] | Rapid cooling in air or water |
| S32506 | 1870-2050 °F [1020-1120°C] | Rapid cooling in air or water |
| S32304 | 1700-1920 °F [925-1050°C] | Rapid cooling in air or water |
| S32750 | 1880-2060 °F [1025-1125°C] | Rapid cooling in air or water |
| S32760 | 2010-2085 °F [1100-1140°C] | Rapid cooling in air or water |
| S32950 | 1820-1880 °F [990-1025°C] | Rapid cooling in water |
| S32520 | 1975-2050 °F [1080-1120°C] | Rapid cooling in air or water |
Referenced Documents
- ASTM A370 Test Methods and Definitions for Mechanical Testing of Steel Products
- A923 Test Methods for Detecting Detrimental Intermetallic Phase in Duplex Austenitic/Ferritic Stainless Steel
- ASTM A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
- ASTM A999/A999M Specification for General Requirements for Alloy and Stainless Steel Pipe
- ASTM E213 Practice for Ultrasonic Examination of Metal Pipe and Tubing
- ASTM E309 Practice for Eddy-Current Examination of Steel Tubular Products Using Magnetic Saturation
- ASTM E381 Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings
- ASTM E426 Practice for Electromagnetic (Eddy-Current) Examination of Seamless and Welded Tubular Products, Austenitic Stainless Steel and Similar Alloys
- ASTM E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
- ASTM A5.9 Corrosion-Resisting Chromium and Chromium-Nickel Steel Welding Rods and Electrodes
- ASTM B1.20.1 Pipe Threads, General Purpose
- ASTM B36.10 Welded and Seamless Wrought Steel Pipe
- ASTM B36.19 Stainless Steel Pipe
ASME SA 790 Mechanical Tests Required
1. Tension Tests-One tension test shall be made on a specimen for lots of not more than 50 tubes. Tension tests shall be made on specimens from two tubes for lots of more than 50 tubes (see Note 2).
2. Flaring Test (for Seamless Tubes)-One test shall be made on specimens from one end of one tube from each lot (see Note 1) of finished tubes. The minimum expansion of the inside diameter shall be 10 %.
3. Flange Test (for Welded Tubes)-One test shall be made on specimens from one end of one tube from each lot (see Note1) of finished tubes.
4. Hardness Test-Brinell or Rockwell hardness tests shall be made on specimens from two tubes from each lot (see Note 2).
5. Reverse Flattening Test-For welded tubes, one reverse flattening test shall be made on a specimen from each 1500 ft [450 m] of finished tubing.
When more than one heat is involved, the tension, flaring, flanging, and hardness test requirements shall apply to each heat.
