ASTM A790 UNS S31803 Duplex Stainless Steel Pipe
ASTM A790 UNS S31803 Steel Pipe covers seamless and straight-seam welded ferritic/austenitic steel pipe intended for general corrosive service, with particular emphasis on resistance to stress corrosion cracking.
Description
ASTM A790 UNS S31803 Duplex Stainless Steel Pipe
Standard:ASTM A790/A790M − 16
Standard Specification for
Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASTM A790 UNS S31803 Steel Pipe covers seamless and straight-seam welded ferritic/austenitic steel pipe intended for general corrosive service, with particular emphasis on resistance to stress corrosion cracking.
Materials and Manufacture
Manufacture:
The pipes are made by the seamless or an automatic welding process, with no addition of filler metal in the welding operation.
pipe may be either hot-finished or cold-finished.
The pipes are pickled free of scale. When bright annealing is used, pickling is not necessary.
Heat-Treated
all pipe are furnished in the heat-treated condition as shown in Table 1.
TABLE 1 Heat Treatment
| UNS Designation |
Temperature °F [°C] | Quench |
| S31803 | 1870–2010[1020–1100] | Rapid cooling in air or water |
Chemical Composition
| UNS Designation |
C | Mn | P | S | Si | Ni | Cr | Mo | N |
| S31803 | 0.030 | 2.00 | 0.030 | 0.020 | 1.00 | 4.5–6.5 | 21.0–23.0 | 2.5–3.5 | 0.08–0.20 |
Mechanical Properties
| UNS Designation |
Type A | Tensile Strength, min, ksi[MPa] |
Yield Strength, min,ksi [MPa] |
Elongation in 2 in. or 50 mm,min, % |
Hardness, max | |
| HBW | HRC | |||||
| S31803 | 90 [620] | 65 [450] | 25 | 290 | 30 | |
Workmanship, Finish, and Appearance
The finished pipes shall be reasonably straight and shall have a workmanlike finish.
Mechanical Tests Required
Transverse or Longitudinal Tension Test
Mechanical Testing Lot Definition
Flattening Tes
Hardness Test
Hydrostatic or Nondestructive Electric Test
Product Marking
the marking include the manufacturer’s private identifying mark and whether the pipe is seamless or welded. If specified in the purchase order, the marking for pipe larger than NPS 4 shall include the weight.