ASTM A949 Seamless Ferritic/Austenitic Stainless Steel Pipe
ASTM A949/A949M
Standard Specification for
Spray-Formed Seamless Ferritic/Austenitic Stainless Steel Pipe
1. Scope
1.1 This specification covers spray-formed seamless ferritic/austenitic stainless steel pipe intended for general corrosive service, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.
1.2 Optional supplementary requirements are provided for pipe where a greater degree of testing is desired. These supplementary requirements call for additional tests to be made and when desired, one or more of these may be specified in the order.
1.3 Appendix X1 ofthis specification lists the dimensions of seamless stainless steel pipe as shown in ANSI B 36.19. Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification.
1.4 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.
1.4.1 Within the text, the SI units are shown in brackets.
1.4.2 The inch-pound units shall apply unless the “M”designation of this specification is specified in the order.
NOTE 1—The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter,” “size,” and “nominal size.”
2. Referenced Documents
2.1 ASTM Standards:
A450/A450M Specification for General Requirements for Carbon and Low Alloy Steel Tubes
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
A999/A999M Specification for General Requirements for Alloy and Stainless Steel Pipe
E381 Method of Macroetch Testing Steel Bars, Billets,Blooms, and Forgings
E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
2.2 ANSI/ASME Standards:
B 1.20.1 Pipe Threads, General Purpose
B 36.10M-1995 Welded and Seamless Wrought Steel Pipe
B 36.19 Stainless Steel Pipe
2.3 Other Standard:
SAE J1086 Practice for Numbering Metals and Alloys (UNS)
3. Terminology
3.1 Definitions:
3.1.1 For definitions ofterms used in this specification, refer to Terminology A941.
3.2 Definitions ofTerms Specific to This Standard:
3.2.1 spray-formed—denotes the fabrication of different shapes of a metallic material by deposition of a spray,consisting of droplets, solid particles, and particles that are partially solid, onto a moving substrate.
3.2.1.1 Discussion—The spray is produced by gas atomization of the liquid metal or alloy. On impingement with the substrate, the species of the spray consolidate and solidify completely to produce a product that is essentially free of porosity. The metallurgical characteristics of the spray-formed product are controlled primarily by the thermal condition ofthe spray, and that of the surface of the metallic deposit formed on the substrate.
4. Ordering Information
4.1 Orders for material under this specification should include the following, as required, to describe the desired material adequately:
4.1.1 Quantity (feet, metres, or number of lengths),
4.1.2 Name of material (ferritic/austenitic steel pipe),
4.1.3 Grade (Table 1),
4.1.4 Size (NPS designator or outside diameter and schedule number of average wall thickness, or other),
4.1.5 Length (specific or random) (Section 10),
4.1.6 End finish (section on Ends of Specification A999/A999M),
4.1.7 Optional requirements (Section 9), Supplementary Requirements S1 to S4,
4.1.8 Test report required (section on Certification of Specification A999/A999M),
4.1.9 Specification designation, and
4.1.10 Special requirements or exceptions to the specification.
5. General Requirements
5.1 Material furnished under this specification shall conform to the applicable requirements of the current edition of Specification A999/A999M unless otherwise provided herein.
6. Materials and Manufacture
6.1 Melting—The steel shall be made by the electric-furnace process or other primary processes approved by the purchaser.
6.2 Pipe Manufacture:
6.2.1 The pipe shall be made by the spray forming process using the melt from the primary melting as noted in 7.1.
6.2.2 The pipe shall be made by spraying the melt on to a thin-walled collector tube. The as spray formed tube shall be machined on both the inner and outer surfaces. The remaining metal shall be homogeneous, sound, and meet the requirements of Section 11.
6.2.3 Unless specified by the purchaser, pipe may be furnished as spray formed or as spray-formed and cold-finished.
6.2.4 All pipe shall be furnished in the heat-treated condition as shown in Table 1.
6.2.5 All pipe shall be furnished in the descaled condition and be free of contaminating iron particles. Pickling, blasting or surface finishing is not mandatory when pipe is bright annealed. The purchaser may request that a passivating treatment be applied.
7. Chemical Composition
7.1 The steel shall conform to the chemical requirements as prescribed in Table 2.
8. Product Analysis
8.1 At the request of the purchaser, an analysis of two pipes from each lot shall be made by the manufacturer. A lot of pipe shall consist of the following number of lengths of the same size and wall thickness from any one heat of stainless steel:
8.2 The results of these analyses shall be reported to the purchaser or the purchaser’s representative, and shall conform to the requirements specified in Section 5.
8.3 If the analysis of one of the tests specified in 8.1 does not conform to the requirements specified in Section 5, an analysis of each pipe from the same heat or lot may be made,and all pipes conforming to the requirements shall be accepted.
9. Tensile and Hardness Properties
9.1 The material shall conform to the tensile and hardness properties prescribed in Table 3.
10. Lengths
10.1 Pipe lengths shall be in accordance with the following regular practice:
10.1.1 Unless otherwise agreed upon, all sizes from NPS 1 ⁄ 8 to and including NPS 8 are available in a length up to 24 ft (Note 2) with the permissible range of 15 to 24 ft (Note 2).Short lengths are acceptable and the number and minimum length shall be agreed upon between the manufacturer and the purchaser.
NOTE 2—This value applies when the inch-pound designation of this specification is the basis of purchase. When the “M” designation of this specification is the basis of purchase, the corresponding metric value(s) shall be agreed upon between the manufacturer and the purchaser.
10.1.2 If definite cut lengths are desired, the lengths required shall be specified in the order. No pipe shall be less than the specified length and no more than 1 ⁄ 4 in. [6 mm] over it.
11. Workmanship, Finish, and Appearance
11.1 The finished pipes shall be reasonably straight and shall have a workmanlike finish. Imperfections may be removed by grinding, provided the wall thicknesses are not decreased to less than that permitted, in the Permissible Variations in Wall Thickness Section of Specification A999/A999M.
12. Mechanical Tests Required
12.1 Transverse or Longitudinal Tension Test—One tension test shall be made on a specimen for lots of not more than 100 pipes. Tension tests shall be made on specimens from two pipes for lots of more than 100 pipes.
NOTE 3—The term “lot,” for mechanical tests, applies to all pipe of the same nominal size and wall thickness (or schedule) that is produced from the same heat ofsteel and subjected to the same finishing treatment: (1) in a continuous heat-treatment furnace, or (2) in a batch-type heat-treatment furnace, equipped with recording pyrometers and automatically controlled within a 50°F [30°C] range, the larger of: (a) each 200 ft [60 m] or fraction thereof or, (b) that pipe heat treated in the same batch furnace charge.
Standard Specification for
Spray-Formed Seamless Ferritic/Austenitic Stainless Steel Pipe
1. Scope
1.1 This specification covers spray-formed seamless ferritic/austenitic stainless steel pipe intended for general corrosive service, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.
1.2 Optional supplementary requirements are provided for pipe where a greater degree of testing is desired. These supplementary requirements call for additional tests to be made and when desired, one or more of these may be specified in the order.
1.3 Appendix X1 ofthis specification lists the dimensions of seamless stainless steel pipe as shown in ANSI B 36.19. Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification.
1.4 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.
1.4.1 Within the text, the SI units are shown in brackets.
1.4.2 The inch-pound units shall apply unless the “M”designation of this specification is specified in the order.
NOTE 1—The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter,” “size,” and “nominal size.”
2. Referenced Documents
2.1 ASTM Standards:
A450/A450M Specification for General Requirements for Carbon and Low Alloy Steel Tubes
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
A999/A999M Specification for General Requirements for Alloy and Stainless Steel Pipe
E381 Method of Macroetch Testing Steel Bars, Billets,Blooms, and Forgings
E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
2.2 ANSI/ASME Standards:
B 1.20.1 Pipe Threads, General Purpose
B 36.10M-1995 Welded and Seamless Wrought Steel Pipe
B 36.19 Stainless Steel Pipe
2.3 Other Standard:
SAE J1086 Practice for Numbering Metals and Alloys (UNS)
3. Terminology
3.1 Definitions:
3.1.1 For definitions ofterms used in this specification, refer to Terminology A941.
3.2 Definitions ofTerms Specific to This Standard:
3.2.1 spray-formed—denotes the fabrication of different shapes of a metallic material by deposition of a spray,consisting of droplets, solid particles, and particles that are partially solid, onto a moving substrate.
3.2.1.1 Discussion—The spray is produced by gas atomization of the liquid metal or alloy. On impingement with the substrate, the species of the spray consolidate and solidify completely to produce a product that is essentially free of porosity. The metallurgical characteristics of the spray-formed product are controlled primarily by the thermal condition ofthe spray, and that of the surface of the metallic deposit formed on the substrate.
4. Ordering Information
4.1 Orders for material under this specification should include the following, as required, to describe the desired material adequately:
4.1.1 Quantity (feet, metres, or number of lengths),
4.1.2 Name of material (ferritic/austenitic steel pipe),
4.1.3 Grade (Table 1),
4.1.4 Size (NPS designator or outside diameter and schedule number of average wall thickness, or other),
4.1.5 Length (specific or random) (Section 10),
4.1.6 End finish (section on Ends of Specification A999/A999M),
4.1.7 Optional requirements (Section 9), Supplementary Requirements S1 to S4,
4.1.8 Test report required (section on Certification of Specification A999/A999M),
4.1.9 Specification designation, and
4.1.10 Special requirements or exceptions to the specification.
5. General Requirements
5.1 Material furnished under this specification shall conform to the applicable requirements of the current edition of Specification A999/A999M unless otherwise provided herein.
6. Materials and Manufacture
6.1 Melting—The steel shall be made by the electric-furnace process or other primary processes approved by the purchaser.
6.2 Pipe Manufacture:
6.2.1 The pipe shall be made by the spray forming process using the melt from the primary melting as noted in 7.1.
6.2.2 The pipe shall be made by spraying the melt on to a thin-walled collector tube. The as spray formed tube shall be machined on both the inner and outer surfaces. The remaining metal shall be homogeneous, sound, and meet the requirements of Section 11.
6.2.3 Unless specified by the purchaser, pipe may be furnished as spray formed or as spray-formed and cold-finished.
6.2.4 All pipe shall be furnished in the heat-treated condition as shown in Table 1.
6.2.5 All pipe shall be furnished in the descaled condition and be free of contaminating iron particles. Pickling, blasting or surface finishing is not mandatory when pipe is bright annealed. The purchaser may request that a passivating treatment be applied.
TABLE 1 Heat Treatment
|
UNS Designation |
Temperature | Quench |
| S31803 | 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 |
| S31200 | 1920–2010°F [1050–1100°C] | rapid cooling in water |
| S32550 | 1900°F [1040°C] min | rapid cooling in air or water |
| S31260 | 1870–2010°F [1020–1100°C] | rapid cooling in 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 |
| S32900 | 1700–1750°F [925–955°C] | rapid cooling in air or water |
| S32950 | 1820–1880°F [995–1025°C] | air cool |
7. Chemical Composition
7.1 The steel shall conform to the chemical requirements as prescribed in Table 2.
8. Product Analysis
8.1 At the request of the purchaser, an analysis of two pipes from each lot shall be made by the manufacturer. A lot of pipe shall consist of the following number of lengths of the same size and wall thickness from any one heat of stainless steel:
| NPS Designator | Lengths of Pipe in Lot |
| Under 2 | 400 or fraction thereof |
| 2 to 5, incl | 200 or fraction thereof |
| 6 and over | 100 or fraction thereof |
8.2 The results of these analyses shall be reported to the purchaser or the purchaser’s representative, and shall conform to the requirements specified in Section 5.
8.3 If the analysis of one of the tests specified in 8.1 does not conform to the requirements specified in Section 5, an analysis of each pipe from the same heat or lot may be made,and all pipes conforming to the requirements shall be accepted.
9. Tensile and Hardness Properties
9.1 The material shall conform to the tensile and hardness properties prescribed in Table 3.
10. Lengths
10.1 Pipe lengths shall be in accordance with the following regular practice:
10.1.1 Unless otherwise agreed upon, all sizes from NPS 1 ⁄ 8 to and including NPS 8 are available in a length up to 24 ft (Note 2) with the permissible range of 15 to 24 ft (Note 2).Short lengths are acceptable and the number and minimum length shall be agreed upon between the manufacturer and the purchaser.
NOTE 2—This value applies when the inch-pound designation of this specification is the basis of purchase. When the “M” designation of this specification is the basis of purchase, the corresponding metric value(s) shall be agreed upon between the manufacturer and the purchaser.
10.1.2 If definite cut lengths are desired, the lengths required shall be specified in the order. No pipe shall be less than the specified length and no more than 1 ⁄ 4 in. [6 mm] over it.
11. Workmanship, Finish, and Appearance
11.1 The finished pipes shall be reasonably straight and shall have a workmanlike finish. Imperfections may be removed by grinding, provided the wall thicknesses are not decreased to less than that permitted, in the Permissible Variations in Wall Thickness Section of Specification A999/A999M.
12. Mechanical Tests Required
12.1 Transverse or Longitudinal Tension Test—One tension test shall be made on a specimen for lots of not more than 100 pipes. Tension tests shall be made on specimens from two pipes for lots of more than 100 pipes.
NOTE 3—The term “lot,” for mechanical tests, applies to all pipe of the same nominal size and wall thickness (or schedule) that is produced from the same heat ofsteel and subjected to the same finishing treatment: (1) in a continuous heat-treatment furnace, or (2) in a batch-type heat-treatment furnace, equipped with recording pyrometers and automatically controlled within a 50°F [30°C] range, the larger of: (a) each 200 ft [60 m] or fraction thereof or, (b) that pipe heat treated in the same batch furnace charge.