ASTM B622 UNS N06022 for reactor vessel seamless pipes
ASTM B622 UNS N06022 is a specification for seamless tubing made of Hastelloy C22 (a nickel-chromium-molybdenum-tungsten alloy), a highly corrosion-resistant alloy suitable for use in high-temperature reactor vessels. Key requirements include chemical composition, mechanical properties (tensile strength, yield strength, elongation), and mandatory testing such as hydrostatic pressure testing, tensile testing, and non-destructive electrical testing. These tubings are manufactured without welds, enhancing their strength and pressure resistance. Unless otherwise specified, tubing is supplied in a solution annealed and descaled condition.
What is the C22 material grade?
C22 alloy is a nickel-chromium-molybdenum solid solution-strengthened high-temperature alloy with a chemical composition of 56% nickel, 22% chromium, and 13% molybdenum, with additions of iron, tungsten, and cobalt. It is commonly known by the trade name Hastelloy C22 and the common designation UNS N06022.
Hastelloy C22 Cold Finished Pipes Equivalent Grades
| STANDARD | WERKSTOFF NR. | UNS | JIS | GOST | EN | OR |
| Hastelloy C22 | 2.4602 | N06022 | NW 6022 | - | NiCr21Mo14W | - |
Hastelloy C22 Clad Pipes Chemical Composition
| Grade | C | Mn | Si | S | Co | Ni | Cr | Fe | Mo | P |
| C22 | 0.010 max | 0.50 max | 0.08 max | 0.02 max | 2.50 max | 50.015 min* | 20.00 – 22.50 | 2.00 – 6.00 | 12.50 – 14.50 | 0.02 max |
Mechanical Properties of ASTM B622 UNS N06022 Seamless Pipes
| Element | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| Hastelloy C22 | 8.69 g/cm3 | 1399 °C (2550 °F) | Psi – 1,00,000 , MPa – 690 | Psi – 45000 , MPa – 310 | 45 % |
Hastelloy UNS N06022 Tubing Specification
| ASTM/ ASME Specification | ASTM B619/ ASME SB 619, ASTM B622 / ASME SB 622 Standard Specification for Seamless & Welded Superheater, Condenser, Hydraulic, Boiler and Heat-Exchanger Tubes |
| Shapes | Hastelloy UNS N06022 Round, Rectangular, Square, Hydraulic, Straight, "U" Shape, Coiled, Honed Tubes, Pan Cake Coils |
| Manufacturing Type | Seamless / ERW / Welded / Fabricated / CDW / CDS / DOM / CEW / 100% X Ray Welded |
| Thickness Range | SCH 5, SCH10, SCH 40, SCH 80, SCH 80S, SCH 160, SCH XXH, SCH XXS, SCH XS |
| Swg & Bwg | 10 Swg., 12 Swg., 14 Swg., 16 Swg., 18 Swg., 20 Swg. |
| Standard | SUS, JIS, AISI, ASTM, GB, DIN, EN |
| Delivery Condition | Annealed and Pickled (AP), Polished, Bright Annealed (BA), Cold Drawn, MF |
Material Properties and Applications
Alloy: Hastelloy C22, a nickel-chromium-molybdenum-tungsten alloy, offers excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.
Suitability: Suitable for high-temperature environments and applications involving corrosive chemicals, such as high-temperature impure inorganic and organic acids and seawater.
Composition: The chemical composition of the alloy must meet specific requirements.
Specifications and Production
Standard: ASTM B622, which specifically covers seamless pipe.
Manufacture: Seamless pipe is produced by perforating a solid metal billet to form a hollow tube, resulting in a uniform structure without welds.
Condition: This standard requires pipe to be supplied in the solution annealed and descaled condition, unless a controlled atmosphere is used, in which case descaling is not required.
Size Limitations: This specification is limited to pipe with an outside diameter of 3.5 inches (88.9 mm) or less.
Mechanical Properties and Testing Requirements
Mechanical Properties: The pipe must meet specific requirements for tensile strength, yield strength, and elongation. Mandatory Testing: All pipes must undergo hydrostatic, tensile, and non-destructive electrical testing to ensure quality and reliability.
Verification: Calculate the weight of each pipe and determine its chemical composition.
Gnee Steel specializes in the production and sale of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. Gnee Steel's products are widely used in aerospace, chemical, electric power, automotive, and nuclear energy applications. We also offer customized alloy solutions tailored to customer needs. For alloy pricing inquiries or customized alloy solutions, please contact us for a quote at ss@gneesteel.com.
