Incoloy 800HT is a nickel-iron-chromium alloy that offers excellent resistance to oxidation and carburization at elevated temperatures. This high-performance alloy is particularly well-suited for use in high-temperature process applications where strength and corrosion resistance are important considerations. In this article, we will explore the properties, applications, and equivalents of Incoloy 800HT.
Introduction to Incoloy 800HT
Incoloy 800HT is a variant of Incoloy 800, an alloy that was first developed in the 1950s by Anton Metal Corporation. It is a solid-solution strengthened alloy that features high-strength and excellent resistance to oxidation, carburization, and other forms of high-temperature corrosion. The HT in the alloy’s name stands for “high temperature,” which highlights its exceptional performance in extreme heat environments.
Chemical Composition of Incoloy 800HT
The chemical composition of Incoloy 800HT includes nickel (30-35%), iron (39.5%), chromium (19-23%), manganese (1.5%), silicon (1%) and copper (0.75%). Carbon content in Incoloy 800HT is limited to 0.10%, while aluminum (0.15-0.60%) and titanium (0.15-0.60%) are added for strengthening purposes.
Mechanical Properties of Incoloy 800HT
The mechanical properties of Incoloy 800HT depend on the processing conditions and the final product form. For instance, the mechanical properties of pipe, plate, strip, and round bar can vary significantly. However, generally speaking, Incoloy 800HT has a tensile strength of 75 ksi, a yield strength of 30 ksi, and an elongation of 30%.
Process Service Conditions
Incoloy 800HT is designed to withstand high-temperature service conditions, including exposure to oxidizing and reducing environments. It is typically used in applications where temperatures range from 1200°F to 1600°F (649°C to 871°C). The alloy can handle cyclic heating and cooling without undergoing damage, making it an ideal material for use in thermal processing equipment.
Applications of Incoloy 800HT
Incoloy 800HT finds extensive use in high-temperature processing applications, particularly in the chemical, petrochemical, and power generation industries. Some common applications include:
- Furnace components: Incoloy 800HT is commonly used in furnace components such as muffles, retorts, and radiant tubes.
- Heat exchangers: The alloy exhibits good thermal conductivity and resistance to corrosion, making it an ideal material for use in heat exchangers.
- Power generation equipment: Incoloy 800HT is used in power generation equipment such as steam turbines and boilers due to its excellent strength and corrosion resistance.
- Chemical processing equipment: The alloy is widely used in chemical processing equipment due to its exceptional resistance to acidic and alkaline solutions.
- Industrial piping systems: Incoloy 800HT is an excellent material for high-temperature piping systems, particularly in corrosive environments.
Equivalent Grades of Incoloy 800HT
Incoloy 800HT has several equivalent grades, including:
- UNS N08811
- Werkstoff Nr. 1.4959
- AFNOR Z8NC32-21
- BS NA 15
- ASTM B409
Standard Specification for Incoloy 800HT
The standard specification for Incoloy 800HT is ASTM B407, which covers seamless pipes and tubes made from nickel-chromium-iron alloys. Other relevant specifications include ASTM B163 (seamless nickel and nickel alloy condenser and heat exchanger tubes) and ASTM B514 (welded nickel and nickel alloy pipe).
Conclusion
Incoloy 800HT is a high-performance alloy that offers excellent resistance to oxidation, carburization, and other forms of high-temperature corrosion. The alloy finds extensive use in high-temperature processing applications such as furnaces, heat exchangers, power generation equipment, chemical processing equipment, and piping systems due to its exceptional strength and corrosion resistance. Incoloy 800HT is available in several product forms, including pipe, plate, strip, and round bar, and has several equivalent grades, including UNS N08811 and Werkstoff Nr. 1.4959.
Post time: Jun-03-2023
