ASTM B622
ASTM B622 Basic Info
ASTM B622 encompasses various material grade codes for seamless nickel and nickel-cobalt-chromium-molybdenum-iron alloys tubes. Notable grades include Alloy 625 (UNS N06625) and Alloy C276 (UNS N10276), renowned for their exceptional corrosion resistance and high temperature performance. These materials are extensively utilized in industries such as chemical processing, aerospace, and marine engineering, where reliability and durability in harsh environments are paramount.
Characteristics of ASTM B622
- High Corrosion Resistance: ASTM B622 steel exhibits exceptional resistance to corrosion, including both general corrosion and localized corrosion. This makes it well-suited for use in environments where exposure to corrosive substances is common, such as chemical processing plants and marine applications.
- High-Temperature Resistance: ASTM B622 steel is designed to withstand high temperatures, making it suitable for applications in industries such as power generation and aerospace, where elevated temperatures are encountered. Its ability to maintain structural integrity and performance at high temperatures enhances its reliability in demanding environments.
- Seamless and Welded Construction: ASTM B622 steel pipes are available in both seamless and welded construction. This versatility allows for flexibility in design and installation, catering to various project requirements. The seamless construction ensures uniformity and integrity, while welded options provide cost-effective solutions without compromising on performance.
ASTM B622 Data Sheet
Steel Grade
Dimensions and Tol.
Equivalent Steel Grades
Chemical Composition
Mechanical Properties
Fabrication and Welding
Steel Grade
Alloy C276
Alloy C22
Alloy B2
Alloy B3
Alloy G30
Alloy N10276
Alloy N06022
Alloy N10665
Alloy N10675
Alloy N06030
Alloy N06059
Alloy N06455
Alloy N06200
Alloy N06686
Alloy N06445
Dimensions and Tol.
Round Pipes
- Outer Diameter: 1/8″ – 6″ (3.18 mm – 152.4 mm)
- Thickness: Schedule 5S – Schedule XXS
- Length: Random or Specific Lengths
- Straightness: 1/8″ in any 5 ft (3.18 mm in any 1.5 m)
- Ovality: Maximum of 2% of nominal diameter
- Tolerance on Outside Diameter: ±1%
- Tolerance on Wall Thickness: ±12.5%
Rectangular Pipe
- Width: Up to 6″ (152.4 mm)
- Height: Up to 4″ (101.6 mm)
- Thickness: Schedule 5S – Schedule XXS
- Length: Random or Specific Lengths
- Straightness: 1/8″ in any 5 ft (3.18 mm in any 1.5 m)
- Corner Radii: Maximum of 1/8″ (3.18 mm)
- Tolerance on Width: ±1%
- Tolerance on Thickness: ±12.5%
Square Pipes
- Width: Up to 4″ (101.6 mm)
- Thickness: Schedule 5S – Schedule XXS
- Length: Random or Specific Lengths
- Straightness: 1/8″ in any 5 ft (3.18 mm in any 1.5 m)
- Corner Radii: Maximum of 1/8″ (3.18 mm)
- Tolerance on Width: ±1%
- Tolerance on Thickness: ±12.5%
Equivalent Steel Grades
United States:
Equivalent Grades: UNS N10276, UNS N06022, UNS N06035, UNS N06030
Standard: ASTM B622, ASTM B619, ASTM B626
Germany:
Equivalent Grades: 2.4819, 2.4602, 2.4610, 2.4607
Standard: DIN 17751, DIN 17752
Japan:
Equivalent Grades: NW 0276, NW 6022, NW 6025, NW 6020
Standard: JIS G3463, JIS G3459
France:
Equivalent Grades: NiMo16Cr15W, NiMo16Cr16Ti
Standard: AFNOR NF A49-214, NF A49-215
Chemical Composition
UNS N10276 (Alloy C276):
- Carbon (C): 0.01 max
- Manganese (Mn): 1.00 max
- Phosphorus (P): 0.04 max
- Sulfur (S): 0.03 max
- Silicon (Si): 0.08 max
- Chromium (Cr): 14.5 – 16.5
- Molybdenum (Mo): 15.0 – 17.0
- Tungsten (W): 3.0 – 4.5
- Cobalt (Co): 2.5 max
- Iron (Fe): 4.0 – 7.0
- Nickel (Ni): Balance
UNS N06022 (Alloy C22):
- Carbon (C): 0.010 max
- Manganese (Mn): 0.50 max
- Phosphorus (P): 0.025 max
- Sulfur (S): 0.020 max
- Silicon (Si): 0.08 max
- Chromium (Cr): 20.0 – 22.5
- Molybdenum (Mo): 12.5 – 14.5
- Iron (Fe): 2.0 – 6.0
- Nickel (Ni): Balance
UNS N06035 (Alloy B3):
- Carbon (C): 0.01 max
- Manganese (Mn): 1.00 max
- Phosphorus (P): 0.04 max
- Sulfur (S): 0.03 max
- Silicon (Si): 0.08 max
- Chromium (Cr): 1.0 max
- Molybdenum (Mo): 1.0 max
- Iron (Fe): 2.0 – 6.0
- Nickel (Ni): Balance
UNS N06030 (Alloy G30):
- Carbon (C): 0.03 max
- Manganese (Mn): 1.00 max
- Phosphorus (P): 0.04 max
- Sulfur (S): 0.03 max
- Silicon (Si): 0.08 max
- Chromium (Cr): 29.0 – 32.0
- Molybdenum (Mo): 4.0 – 6.0
- Iron (Fe): 1.5 – 3.0
- Nickel (Ni): Balance
Mechanical Properties
UNS N10276 (Alloy C276):
- Tensile Strength (ksi): 110-130
- Tensile Strength (MPa): 760-895
- Yield Strength (0.2% Offset) (ksi): 45-65
- Yield Strength (MPa): 310-450
- Elongation (%): 40 min
UNS N06022 (Alloy C22):
- Tensile Strength (ksi): 110-120
- Tensile Strength (MPa): 760-830
- Yield Strength (0.2% Offset) (ksi): 40-50
- Yield Strength (MPa): 275-345
- Elongation (%): 45 min
UNS N06035 (Alloy B3):
- Tensile Strength (ksi): 110-120
- Tensile Strength (MPa): 760-830
- Yield Strength (0.2% Offset) (ksi): 40-50
- Yield Strength (MPa): 275-345
- Elongation (%): 45 min
UNS N06030 (Alloy G30):
- Tensile Strength (ksi): 90-110
- Tensile Strength (MPa): 620-760
- Yield Strength (0.2% Offset) (ksi): 35-45
- Yield Strength (MPa): 240-310
- Elongation (%): 40 min
Fabrication and Welding
Hot Working:
- Steel can be hot worked within a temperature range of 1600°F to 2250°F (870°C to 1230°C).
- Hot working should be performed carefully to avoid excessive deformation and distortion of the material.
Cold Working:
- ASTM B444 steel can be cold worked using standard methods such as cold drawing, cold rolling, or cold forging.
- Cold working may result in increased strength and hardness but should be followed by annealing for optimal properties.
Machining:
- ASTM B444 steel is generally machinable using conventional machining techniques.
- Carbide tooling is recommended for improved tool life and surface finish.
- Coolants or lubricants may be necessary to minimize heat generation and tool wear.
Welding:
- ASTM B444 steel can be welded using various welding techniques such as gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and shielded metal arc welding (SMAW).
- Preheating may be required to minimize the risk of cracking, especially for thicker sections.
- Post-weld heat treatment (PWHT) is often recommended to relieve residual stresses and improve mechanical properties.
- Suitable filler metals include AWS A5.14 ERNiCrMo-4 and ERNiCrMo-7 for nickel-chromium-molybdenum alloys.
- Welds should be inspected thoroughly to ensure integrity and compliance with specifications.
Heat Treatment:
- ASTM B444 steel may undergo heat treatment processes such as annealing or stress relieving to improve ductility, toughness, and dimensional stability.
- Annealing is typically performed at temperatures between 1900°F to 2100°F (1040°C to 1150°C), followed by rapid cooling for optimal results.
- Stress relieving is done at lower temperatures to remove residual stresses without affecting material properties.
