ASME SA268 pdf download

ASME SA268 pdf download SPECIFICATION FOR SEAMLESS AND WELDED FERRITIC AND MARTENSITIC STAINLESS STEEL TUBING FOR GENERAL SERVICE
1. Scope
1.1 This specification covers a number of grades of nominal-wall-thickness, stainless steel tubing for general corrosion-resisting and high-temperature service. Most of these grades are commonly known as the “straight-chro- mium” types and are characterized by being ferromagnetic. Two of these grades, TP410 and UNS S41500 (Table 1), are amenable to hardening by heat treatment, and the highchromium, ferritic alloys are sensitive to notch-brittleness on slow cooling to ordinary temperatures. These features should be recognized in the use of these materials. Grade TP439 is used primarily for hot-water tank service and does not require post-weld heat treatment to prevent attack of the heat affected zone.
1.2 An optional supplementary requirement is pro- vided, and when desired, shall be so stated in the order.
1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each systemmustbe usedindependentlyofthe other. Combining values fromthe two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the “M” designation ofthis specification is specified in the order.
2. Referenced Documents
2.1 ASTM Standards: A 480/A 480M Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip A 763 Practices for Detecting Susceptibility to Intergranu- lar Attack in Ferritic Stainless Steels 423 A 1016/A 1016M Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes E 213 Practice for Ultrasonic Examination of Metal Pipe and Tubing E 273 Practice for Ultrasonic Examination of the Weld Zone of Welded Pipe and Tubing
3. Terminology
3.1 Lot Definitions:
3.1.1 For flange and flaring requirements, the term lot applies to all tubes, prior to cutting, ofthe same nominal size and wall thickness that are produced from the same heat of steel. If 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. If the final heat treatment is in a continuous furnace, 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 given in Table 2.
3.1.2 For tensile 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. If 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. If the final heat treatment is in a continuous furnace, 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.
4. Ordering Information
4.1 It is the responsibility of the purchaser to specify all requirements that are necessary for material orderedv under this specification. Such requirements may include,but are not limited to, the following:
4.1.1 Quantity (feet, metres, or number of lengths),
4.1.2 Name of material (seamless or welded tubes),
4.1.3 Grade (Table 1),
4.1.4 Size (outside diameter and nominal wall thickness),
4.1.5 Length (specific or random),
4.1.6 Optional requirements (hydrostatic or nondestructive electric test, Section 16),
4.1.7 Test report required (Certification Section of Specification A 1016/A 1016M),
4.1.8 Specification designation,
4.1.9 Intergranular corrosion test, and
4.1.10 Special requirements.
5. General Requirements
5.1 Material furnished under this specification shall conform to the applicable requirements of Specification A 1016/A 1016M unless otherwise provided herein.
6. Manufacture
6.1 The tubes shall be made by the seamless or welded process with no filler metal added.
7. Heat Treatment
7.1 As a final heat treatment, tubes shall be reheated to a temperature of 1200°F [650°C] or higher and cooled (as appropriate for the grade) to meet the requirements of this specification.
7.2 The martensitic grade UNS S41500 shall be reheated to a temperature of 950°F [510°C] or higher and cooled as appropriate to meet the requirements of this specification.