ASTM B408
ASTM B408 Basic Info
ASTM B408 outlines the characteristics of nickel-iron-chromium alloys in the form of rod and bar. These materials exhibit exceptional resistance to corrosion in various environments, making them suitable for applications in chemical processing, marine engineering, and aerospace industries. The standard specifies the chemical composition, mechanical properties, and dimensional tolerances necessary to ensure the reliability and performance of these alloys in demanding conditions.
Characteristics of ASTM B408
- Material Coverage: ASTM B408 specifies the requirements for nickel-iron-chromium alloys in the form of rod, bar, and wire. Alloys covered by this specification include Incoloy 800, 800H, and 800HT, among others.
- Chemical Composition: The standard outlines the chemical composition limits for these nickel-iron-chromium alloys, ensuring consistency and suitability for high-temperature applications.
- Mechanical Properties: ASTM B408 provides guidelines for the mechanical properties of the materials, such as tensile strength, yield strength, and elongation. This helps assess their performance under load.
- Dimensions and Tolerances: The standard includes requirements for dimensions, such as diameter and length, as well as tolerances for these dimensions. This ensures the materials meet the necessary specifications for their intended use.
ASTM B408 Data Sheet
Steel Grade
Dimensions and Tol.
Equivalent Steel Grades
Chemical Composition
Mechanical Properties
Fabrication and Welding
Steel Grade
Incoloy 800:
Nickel-Iron-Chromium Alloy
Incoloy 800H:
Nickel-Iron-Chromium Alloy
Incoloy 800HT:
Nickel-Iron-Chromium Alloy
Incoloy 825:
Nickel-Iron-Chromium-Molybdenum Alloy
Dimensions and Tol.
Round Rod:
Diameter (inches): 0.1875 to 4.000
Tolerance on Diameter (inches): ±0.002
Length (feet): 12, 14
Tolerance on Length (inches): ±1/16 inch
Round Bar:
Diameter (inches): 0.250 to 10.000
Tolerance on Diameter (inches): ±0.003
Length (feet): 12, 14
Tolerance on Length (inches): ±1/16 inch
Wire:
Diameter (inches): 0.010 to 0.625
Length: Coil
Equivalent Steel Grades
Incoloy 800:
- Germany (DIN): DIN 1.4876
- Japan (JIS): JIS NCF 800
- China (GB): GB/T 0Cr20Ni32Al
- United Kingdom (BS): BS NA 15
Incoloy 800H:
- Germany (DIN): —
- Japan (JIS): JIS NCF 800H
- China (GB): GB/T 0Cr20Ni32Al
- United Kingdom (BS): BS NA 15
Incoloy 800HT:
- Germany (DIN): —
- Japan (JIS): JIS NCF 800HT
- China (GB): GB/T 0Cr20Ni32Al
- United Kingdom (BS): BS NA 15
Incoloy 825:
- Germany (DIN): DIN 2.4858
- Japan (JIS): JIS NCF 825
- China (GB): GB/T 0Cr21Ni42Mo3W1
- United Kingdom (BS): BS NA 16
Chemical Composition
Incoloy 800:
- Nickel (Ni): 30.0-35.0
- Iron (Fe): 39.5 min
- Chromium (Cr): 19.0-23.0
- Aluminum (Al): 0.15-0.60
- Titanium (Ti): 0.15-0.60
- Carbon (C): 0.10 max
- Manganese (Mn): 1.50 max
- Sulfur (S): 0.015 max
- Silicon (Si): 1.00 max
Incoloy 800H:
- Nickel (Ni): 30.0-35.0
- Iron (Fe): 39.5 min
- Chromium (Cr): 19.0-23.0
- Aluminum (Al): 0.15-0.60
- Titanium (Ti): 0.15-0.60
- Carbon (C): 0.05-0.10
- Manganese (Mn): 1.50 max
- Sulfur (S): 0.015 max
- Silicon (Si): 1.00 max
Incoloy 800HT:
- Nickel (Ni): 30.0-35.0
- Iron (Fe): 39.5 min
- Chromium (Cr): 19.0-23.0
- Aluminum (Al): 0.15-0.60
- Titanium (Ti): 0.25-0.60
- Carbon (C): 0.06-0.10
- Manganese (Mn): 1.50 max
- Sulfur (S): 0.015 max
- Silicon (Si): 1.00 max
Incoloy 825:
- Nickel (Ni): 38.0-46.0
- Iron (Fe): 22.0 min
- Chromium (Cr): 19.5-23.5
- Carbon (C): 0.05 max
- Manganese (Mn): 1.00 max
- Sulfur (S): 0.03 max
- Silicon (Si): 0.50 max
- Copper (Cu): 1.5-3.0
- Molybdenum (Mo): 2.5-3.5
Mechanical Properties
Incoloy 800:
- Tensile Strength (ksi): 75 min
- Yield Strength (0.2% offset, ksi): 30 min
- Elongation (%): 30 min
Incoloy 800H:
- Tensile Strength (ksi): 75 min
- Yield Strength (0.2% offset, ksi): 30 min
- Elongation (%): 30 min
Incoloy 800HT:
- Tensile Strength (ksi): 75 min
- Yield Strength (0.2% offset, ksi): 30 min
- Elongation (%): 30 min
Incoloy 825:
- Tensile Strength (ksi): 85 min
- Yield Strength (0.2% offset, ksi): 35 min
- Elongation (%): 30 min
Fabrication and Welding
Incoloy 800:
- Fabrication Characteristics: Good resistance to carburization and oxidation at high temperatures. Can be formed using conventional methods such as hot working, cold working, and machining.
- Welding Characteristics: Welding can be done using conventional methods such as gas-tungsten arc welding (GTAW), gas-metal arc welding (GMAW), and shielded metal arc welding (SMAW).
Incoloy 800H:
- Fabrication Characteristics: Similar to Incoloy 800 with added higher carbon content for enhanced high-temperature strength. Can be formed using conventional methods such as hot working, cold working, and machining.
- Welding Characteristics: Welding can be done using conventional methods such as gas-tungsten arc welding (GTAW), gas-metal arc welding (GMAW), and shielded metal arc welding (SMAW).
Incoloy 800HT:
- Fabrication Characteristics: Similar to Incoloy 800 with added higher carbon content and elevated temperature properties. Can be formed using conventional methods such as hot working, cold working, and machining.
- Welding Characteristics: Welding can be done using conventional methods such as gas-tungsten arc welding (GTAW), gas-metal arc welding (GMAW), and shielded metal arc welding (SMAW).
Incoloy 825:
- Fabrication Characteristics: Good resistance to a wide range of corrosive environments including sulfuric acid, phosphoric acid, and seawater. Can be formed using conventional methods such as hot working, cold working, and machining.
- Welding Characteristics: Welding should be performed with Inconel 825 filler metal or matched composition. Post-weld heat treatment may be necessary for certain applications.
ASTM B408 Applications in Aerospace Industry
ASTM B408 materials, specifically the nickel-iron-chromium alloy known as Incoloy 800H, find crucial applications within the aerospace industry due to their exceptional properties. In aerospace, where components must withstand extreme temperatures, pressures, and corrosive environments, ASTM B408 alloys shine.
One primary application is in gas turbine components, such as combustion chambers and afterburners, where Incoloy 800H’s high-temperature strength and resistance to oxidation and carburization are vital. These alloys excel in environments with temperatures exceeding 1000°F (540°C), maintaining their mechanical properties under such demanding conditions.
Additionally, ASTM B408 materials are used in aircraft engine exhaust systems, where they resist sulfur-rich environments and maintain integrity at high temperatures. Their weldability and fabricability also make them suitable for intricate parts. In aerospace, where weight is a critical factor, the balance of strength and lightness in these alloys is advantageous.
Overall, ASTM B408 alloys in the aerospace industry provide reliability, longevity, and performance, ensuring the safety and efficiency of aircraft in some of the most challenging operating conditions. Their ability to withstand thermal cycling, pressure differentials, and corrosive gases makes them indispensable for critical aerospace components.
