• Increased tensile & yield strength
• Good ductility and toughness
• SCC resistance
• Corrosion resistance is better than Duplex
• Cost effective

S32760 Super Duplex Steel Pipe Applications

Oil and gas industry equipment,
Offshore platforms, heat exchangers, process and service water systems, fire-fighting systems, injection and ballast water systems,
Chemical process industries, heat exchanger, vessels, and piping,
Desalination plants, high pressure RO-plants and seawater piping,
Mechanical and structural components, high strength, corrosion-resistant parts,
Power industry FGD systems, utility and industrial scrubber systems, absorber towers, ducting, and piping.

S32760 Super Duplex Steel Pipe Corrosion Resistance

The high chromium and molybdenum content of Super Duplex makes it extremely resistant to uniform corrosion by organic acids like formic and acetic acid. Super Duplex also provides excellent resistance to inorganic acids, especially those containing chlorides.

ASTM A789 / ASME SA789 covers grades of average wall thickness, or, if specified on the order, minimum wall thickness, of stainless steel tubing for services requiring general corrosion resistance, with particular emphasis on resistance to stress corrosion cracking. These steels are suscep- tible to embrittlement if used for prolonged periods at elevated temperatures.

The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Within the text, the SI units are shown in brackets. The inch-pound units shall apply unless the M designation of this specification is specified in the order.

Referenced Documents

ASTM Standards:
A480/A480M Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip
A1016/A1016M Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes
E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)

SAE Standard:
SAE J 1086 Practice for Numbering Metals and Alloys (UNS)

Ordering Information

Quantity (feet, metres, or number of lengths),

Name of product (seamless or welded tubes),

Grade

Size (outside diameter and average wall thickness, unless minimum wall thickness is specified),

Length (specific or random),

Optional requirements (for product analysis, see Section for hydrostatic or nondestructive electric test, see Section 10

Test report required (see the Inspection section of Specification A1016/A1016M

Specification designation, and

Special requirements.

General Requirements

Manufacture

Heat Treatment

All tubes shall be furnished in the heat-treated condition in accordance with the procedures shown in Table 2. For seamless tubes, as an alternate to final heat treatment in a continuous furnace or batch-type furnace, immediately follow- ing hot forming while the temperature of the tubes is not less than the specified minimum solution treatment temperature, tubes may be individually quenched in water or rapidly cooled by other means.

Table.1 ASTM A789 Duplex Steel Chemical Composition

Product Analysis

1. An analysis of either one billet or one length of flat-rolled stock or one tube shall be made from each heat. The chemical composition thus determined shall conform to the requirements specified.

2. A product analysis tolerance (see the annex table on Chemical Requirements (Product Analysis Tolerances) in Specification A480/A480M) shall apply. The product analysis tolerance is not applicable to the carbon content for material with a specified maximum carbon of 0.04 % or less.

3. If the original test for product analysis fails, retests of two additional billets, lengths of flat-rolled stock, or tubes shall be made. Both retests for the elements in question shall meet the requirements of this specification; otherwise, all remaining material in the heat shall be rejected or, at the option of the producer, each billet or tube may be individually tested for acceptance. Billets, lengths of flat-rolled stock, or tubes that do not meet the requirements of this specification shall be re-jected.

NOTE 1—For flange and flaring requirements, the term lot applies to all tubes prior to cutting of the same nominal size and wall thickness that are produced from the same heat of steel. When final heat treatment is in a batch-type furnace, a lot shall include only those tubes of the same size and from the same heat that are heat treated in the same furnace charge. When the final heat treatment is in a continuous furnace, or when heat treated condition is obtained directly by quenching after hot forming, the number of tubes of the same size and from the same heat in a lot shall be determined from the size of the tubes as prescribed in Table 3.

NOTE 2—For tension and hardness test requirements, the term lot applies to all tubes prior to cutting, of the same nominal diameter and wall thickness that are produced from the same heat of steel. When final heat treatment is in a batch-type furnace, a lot shall include only those tubes of the same size and the same heat that are heat treated in the same furnace charge. When the final heat treatment is in a continuous furnace, or when heat treated condition is obtained directly by quenching after hot forming, a lot shall include all tubes of the same size and heat, heat treated in the same furnace at the same temperature, time at heat, and furnace speed, or all tubes of the same size and heat, hot formed and quenched in the same production run.

Mechanical Tests Required

Hydrostatic or Nondestructive Electric Test

1 Each tube shall be subjected to the nondestructive electric test or the hydrostatic test. The type of test to be used shall be at the option of the manufacturer, unless otherwise specified in the purchase order.

2. The hydrostatic test shall be in accordance with Speci- fication A1016/A1016M, except that in the calculation of the hydrostatic test pressure 64000(441.2) shall be substituted for 32000(220.6).

Table.2 Heat Treatment

Tensile Strength and Hardness Requirements

For tubing smaller than 1⁄2 in. [12.7 mm] in outside diameter, the elongation values given for strip specimens in Table 4 shall apply. Mechanical property requirements do not apply to tubing smaller than 1⁄8 in. [3.2 mm] in outside diameter or with walls thinner than 0.015 in. [0.4 mm].
Prior to A789/A789M–04, the values for S32003 were 90 ksi tensile strength and 65 ksi yield strength.

Permissible Variations in Dimensions

1 Variations in outside diameter, wall thickness, and length from those specified shall not exceed the amounts prescribed in Table 5.
2 The permissible variations in outside diameter given in Table 5 are not sufficient to provide for ovality in thin-walled tubes, as defined in the table. In such tubes, the maximum and minimum diameters at any cross section shall deviate from the nominal diameter by no more than twice the permissible variation in outside diameter given in Table 5; however, the mean diameter at that cross section must still be within the given permissible variation.

Surface Condition

All tubes shall be free of excessive mill scale, suitable for inspection. A slight amount of oxidation will not be considered as scale. Any special finish requirements shall be subject to agreement between the manufacturer and the purchaser.

Product Marking

In addition to the marking prescribed in Specification A1016/A1016M, the marking shall indicate whether the tubing is seamless or welded and the wall designation (average wall or minimum wall).