Technical Regulation and Scope of ASTM/ASME A/SA 790 Pipes
The ASTM A790 / A790M (ASME SA790 / SA790M) specification establishes strict requirements for the production of seamless and welded ferritic-austenitic (duplex) steel pipes. This metal product, supplied by EV Group China, is designed for use in aggressive environments where high resistance to stress corrosion cracking is critical.
It is important to consider that these steel grades are prone to embrittlement under prolonged thermal exposure; therefore, their use in high-temperature conditions requires strict adherence to operational parameters.
For projects with increased safety requirements, EV Group China ensures the performance of additional tests, the list of which is agreed upon at the order processing stage.
Geometric parameters of the pipes comply with the recommendations of ANSI B36.19M. We are also prepared to supply products with non-standard dimensions, provided that the physical and mechanical characteristics regulated by the standard are fully maintained.
Measurement unit systems (SI and inch-pound) within this standard are independent. In the absence of an “M” index in the order, values in inch-pounds are considered a priority.
NOTE: The terminology “nominal diameter” and “pipe size” completely replaces the former dimensionless designation NPS.
Chemical Composition of Steel Grades per ASTM A790 / ASME SA790 Standard
| Steel Grade / UNS | C max. | Mn max. | P max. | S max. | Si max. | Ni | Cr | Mo | N | Cu | W |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S31200 | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 5.5-6.5 | 24.0-26.0 | 1.2-2.0 | 0.14-0.2 | – | – |
| S31260 | 0.030 | 1.0 | 0.030 | 0.030 | 0.75 | 5.5-7.5 | 24.0-26.0 | 2.5-3.5 | 0.1-0.3 | 0.2-0.8 | 0.1-0.5 |
| S31500 | 0.030 | 1.2-2.0 | 0.030 | 0.030 | 1.4-2.0 | 4.2-5.2 | 18.0-19.0 | 2.5-3.0 | 0.05-0.1 | – | – |
| S31803 | 0.030 | 2.0 | 0.030 | 0.020 | 1.0 | 4.5-6.5 | 21.0-23.0 | 2.5-3.5 | 0.08-0.2 | – | – |
| S32003 | 0.030 | 2.0 | 0.030 | 0.020 | 1.0 | 3.0-4.0 | 19.5-22.5 | 1.5-2.0 | 0.14-0.2 | – | – |
| S32101 | 0.040 | 4.0-6.0 | 0.040 | 0.030 | 1.0 | 1.35-1.7 | 21.0-22.0 | 0.1-0.8 | 0.2-0.25 | 0.1-0.8 | – |
| S32205 | 0.030 | 2.0 | 0.030 | 0.020 | 1.0 | 4.5-6.5 | 22.0-23.0 | 3.0-3.5 | 0.14-0.2 | – | – |
| S32304 | 0.030 | 2.5 | 0.040 | 0.040 | 1.0 | 3-5.5 | 21.5-24.5 | 0.05-0.6 | 0.05-0.2 | 0.05-0.6 | – |
| S32520 | 0.030 | 1.5 | 0.035 | 0.020 | 0.8 | 5.5-8.0 | 24.0-26.0 | 3.0-5.0 | 0.2-0.35 | 0.5-3.0 | – |
| S32550 | 0.040 | 1.5 | 0.040 | 0.030 | 1.0 | 4.5-6.5 | 24.0-27.0 | 2.9-3.9 | 0.1-0.25 | 1.5-2.5 | – |
| S32750 | 0.030 | 1.2 | 0.035 | 0.020 | 0.8 | 6.0-8.0 | 24.0-26.0 | 3.0-5.0 | 0.24-0.32 | 0.5 | – |
| S32760 | 0.050 | 1.0 | 0.030 | 0.010 | 1.0 | 6.0-8.0 | 24.0-26.0 | 3.0-4.0 | 0.2-0.3 | 0.5-1.0 | 0.5-1.0 |
| S32808 | 0.030 | 1.1 | 0.030 | 0.030 | 0.50 | 7.0-8.5 | 27.0-27.9 | 0.8-1.2 | 0.3-0.4 | – | 2.1-2.5 |
| S32900 | 0.080 | 1.0 | 0.040 | 0.030 | 0.75 | 2.5-5.0 | 23-28 | 1.0-2.0 | – | – | – |
| S32906 | 0.030 | 0.8-1.5 | 0.030 | 0.030 | 0.50 | 5.8-7.5 | 28.0-30.0 | 1.5-2.6 | 0.3-0.4 | 0.8 | – |
| S32950 | 0.030 | 2.0 | 0.035 | 0.010 | 0.60 | 3.5-5.2 | 26.0-29.0 | 1.0-2.5 | 0.15-0.35 | – | – |
| S39274 | 0.030 | 1.0 | 0.030 | 0.020 | 0.80 | 6.0-8.0 | 24.0-26.0 | 2.5-3.5 | 0.24-0.32 | 0.2-0.8 | 1.5-2.5 |
| S39277 | 0.025 | 0.8 | 0.025 | 0.002 | 0.80 | 6.5-8.0 | 24.0-26.0 | 3.0-4.0 | 0.23-0.33 | 1.2-2.0 | 0.8-1.2 |
Mechanical Properties of Ferritic-Austenitic Pipes
| Steel Grade / UNS | Min. Tensile Strength, ksi [MPa] | Min. Yield Strength, ksi [MPa] | Min. Elongation, % | Max. HBW | Max. HRC |
|---|---|---|---|---|---|
| S31200 | 100 / 690 | 65 / 450 | 25 | 280 | – |
| S31260 | 100 / 690 | 65 / 450 | 25 | – | – |
| S31500 | 92 / 630 | 64 / 440 | 30 | 290 | 30 |
| S31803 | 90 / 620 | 65 / 450 | 25 | 290 | 30 |
| S32003 | 90 / 620 | 65 / 450 | 25 | 290 | 30 |
| S32101 (≤ 5mm) | 101 / 700 | 77 / 530 | 30 | 290 | – |
| S32101 (> 5mm) | 94 / 650 | 65 / 450 | 30 | 290 | – |
| S32205 | 95 / 655 | 65 / 450 | 25 | 290 | 30 |
| S32304 | 87 / 600 | 58 / 400 | 25 | 290 | 30 |
| S32520 | 112 / 770 | 80 / 550 | 25 | 310 | – |
| S32550 | 110 / 760 | 80 / 550 | 15 | 297 | 31 |
| S32750 | 116 / 800 | 80 / 550 | 15 | 300 | 32 |
| S32760 | 109 / 750 | 80 / 550 | 25 | 270 | – |
| S32808 | 116 / 800 | 70 / 485 | 15 | 310 | 32 |
| S32900 | 90 / 620 | 94 / 650 | 20 | 271 | 28 |
| S32906 (< 10mm) | 116 / 800 | 94 / 650 | 25 | 300 | 32 |
| S32906 (> 10mm) | 109 / 750 | 80 / 550 | 25 | 300 | 32 |
| S32950 | 100 / 690 | 70 / 480 | 20 | 290 | 30 |
| S39274 | 116 / 800 | 80 / 550 | 15 | 310 | – |
| S39277 | 120 / 825 | 90 / 620 | 25 | 290 | 30 |