ASTM A451-1993 Standard Specification for Centrifugally Cast Austenitic Steel Pipe for High-Temperature Service
This ASTM A451-1993 standard specification covers centrifugally cast austenitic steel pipe for high-temperature service. The pipe shall be heat-treated and shall be designated Type 418 grade 1, Type 441 grade 1, Type 439 grade 1, Type 444 grade 1, or Type 447 grade 1. Mechanical tests shall be performed and shall conform to the specified requirements.
1.1 This ASTM A451-1993 specification is applicable to austenitic stainless steel pipe intended for use in piping systems where a maximum temperature is specified but where no minimum temperature is specified. An improved and more uniform steel can be developed by this method of casting, and thus a higher-temperature service than that obtainable with wrought or cast austenitic steel can be obtained.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parenthesis are provided for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A240/A240M Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A999/A999M Specification for General Requirements for Alloy and Stainless Steel Pipe
2.2 American Society of Mechanical Engineers, Boiler and Pressure Vessel Code:
Section IX Welding and Brazing Qualifications
Section II Materials
3. Terminology
3.1 Definitions Definitions of terms relating to chemical analysis, mechanical properties, weld ability, and other properties shall be in accordance with Terminology A751.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 high-temperature service. Conditions and applications requiring the use of piping, valves, and fittings in the temperature range exceeding 600°F (315°C).
4. Materials and Manufacture
4.1 Steel:
4.1.1 The pipe shall be centrifugally cast of austenitic stainless steel composition conforming to the requirements of specification A240/A240M, and shall be designated as either Type 418 grade 1, Type 441 grade 1, Type 439 grade 1, Type 444 grade 1, or Type 447 grade 1, as ordered.
5. Chemical Composition
5.1 The chemical composition shall conform to the requirements of Table 1.
5.2 If a product analysis is ordered, it shall be performed in accordance with Test Methods, Practices, and Terminology A751.
TABLE 1
Chemical Requirements
Element Type 418
Grade 1 Type 441
Grade 1 Type 439
Grade 1 Type 444
Grade 1 Type 447
Grade 1
Carbon, max 0.03 0.03 0.03 0.025 0.030
Manganese, max 1.00 1.00 1.00 1.00 1.00
Phosphorus, max 0.045 0.040 0.045 0.040 0.045
Sulfur, max 0.030 0.030 0.030 0.015 0.030
Silicon, max 0.75 0.75 0.75 0.75 0.75
Chromium, min 17.0 18.0 18.0 19.5 19.0
Nickel, min 8.0 11.0 11.0 9.5 11.5
Nitrogen 0.25–0.65, min 0.25 0.25 0.25 0.25
Molybdenum, min — — — 2.1 —
Titanium, min 1.0 — — 1.0 —
Columbium, min — 0.10 0.03 0.10 0.10
6. Mechanical Properties
6.1 Tensile Requirements:
6.1.1 The pipe shall conform to the tensile requirements prescribed in Table 2.
6.2 Charpy Impact Testing Requirements:
6.2.1 Where a Charpy impact test is required for the material, it shall conform to the requirements prescribed in Table 3.
TABLE 2
Tensile Requirements
Samples
Yield Strength, min
(0.2% Offset) Tensile Strength, min, psi
(ksi)
Type 418 grade 1 30,000 (206.8) 75,000 (517.3)
Type 441 grade 1 30,000 (206.8) 75,000 (517.3)
Type 439 grade 1 30,000 (206.8) 75,000 (517.3)
Type 444 grade 1 30,000 (206.8) 75,000 (517.3)
Type 447 grade 1 30,000 (206.8) 75,000 (517.3)
TABLE 3
Charpy Impact Testing Requirements
Type Notch Temperature
C(F) ft-lbs
Type 418 grade 1 RT* 15
Type 441 grade 1 RT* 15
Type 439 grade 1 -20(-4) 15
Type 444 grade 1 -20(-4) 20
Type 447 grade 1 -20(-4) 20
*RT = room temperature.
7. Workmanship, Finish, and Appearance
7.1 The pipe shall be reasonably straight and free of any significant kinks, buckles, or other defects.
7.2 The pipe shall have a uniform wall thickness.
7.3 The pipe shall have a smooth, seamless finish.
7.4 The pipe shall be free of any visual defect that significantly affects pipe appearance.
8. Quality Assurance:
8.1 Product analysis and retest shall be in accordance with Test Methods, Practices, and Terminology A751.
9. Unit Weight:
9.1 The approximate unit weights shall conform to the requirements prescribed in Table 4.
TABLE 4
Unit Weight
Type Size Weight per Length, lbs/ft3
Type 418 grade 1 1⁄2 in and over 0.486
Type 441 grade 1 1⁄2 in and over 0.486
Type 439 grade 1 1⁄2 in and over 0.486
Type 444 grade 1 1⁄2 in and over 0.477
Type 447 grade 1 1⁄2 in and over 0.477
10. Dimension:
10.1 The dimensions of the pipe shall be such that they conform to the requirements of Specification A999/A99M.
11. Workmanship
11.1 The pipe shall be cast and finished so that on internal examination various defects, such as blowholes and laminations, are minimized.
12. Weldability
12.1 Weldability requirements shall be as specified in the applicable Code Edition of the American Society of Mechanical Engineers, Boiler and Pressure Vessel Code, Section IX and Section II.
13. Inspection
13.1 Unless otherwise specified in ordering information, the purchaser shall have the right to inspect the pipe and to reject materials as provided for in Specification A999/A99M.
14. Sampling
14.1 Sampling shall be in accordance with Specification A999/A99M.
15. Retests
15.1 Retesting procedures shall be in accordance with Specification A999/A99M.
16. Test Reports
16.1 Test reports shall be provided in accordance with Specification A999/A99M.
