ASTM A790 pipe Standard Specification.pdf
What is ASTM A790 specification?
ASTM A790 is a specification for seamless and welded ferritic/austenitic (duplex) stainless steel pipes for general corrosive service, with a focus on stress corrosion cracking resistance. It details the requirements for manufacturing, heat treatment, and chemical composition to ensure the pipes have high yield strength and excellent corrosion resistance. This standard applies to a variety of duplex and super duplex stainless steels, such as UNS S31803, UNS S32750, and UNS S32760.
What is the composition of ASTM A790 uns S32760?
ASTM A790 UNS S32760 is one of the super duplex stainless steel grades to have high chromium of 25%, nickel of 7%, and molybdenum of 4%. Since A790 S 32760 also contains tungsten and copper, it is best used in aggressive chloride-containing environments for excellent corrosion resistance.
ASTM A790 UNS S32750 Mechanical Properties
ASTM A790 UNS S32750 (also known as Super Duplex 2507) has a minimum tensile strength of 116 ksi (800 MPa) and a minimum yield strength of 80 ksi (550 MPa). The minimum elongation in 2 inches (50mm) is 15%, and the maximum hardness is typically 300 HBW or 32 HRC.
ASTM A790 Stainless steel duplex pipe 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 |
Dimensions of ASTM A790 Welded and Seamless Stainless Steel Pipe
What is the difference between ASTM A790 and A789?
ASTM A789 is for small size tubes and tubing, mainly used for Pressure vessel such as Heat Exchanger. ASTM A790 is big size stainless steel pipe, mainly used for fluid transportation. Both include Seamless and Welded.
What is the difference between ASTM A928 and A790?
ASTM A790 specifies the elements and requirements for the manufacture of seamless and welded pipes, while ASTM A928 covers only electric fusion welded pipes. ASTM A790 requires that duplex and super duplex steel pipes be welded without the addition of any filler metal.
