Product Description

Super austenitic alloys, particularly the 800 and 800H variants, have emerged as critical materials in various industrial applications due to their exceptional physical and chemical properties. Designed to withstand extreme conditions, these alloys offer enhanced mechanical strength and superior resistance to oxidation and corrosion, making them ideal for environments ranging from -20°F to +100°F. This document will explore the physical properties, chemical composition, and industry specifications that delineate the capabilities of Super Austenitic 800/800H alloys.

Physical Properties

Tensile Strength and Yield Strength The following table summarizes the tensile and yield strengths of Super Austenitic 800 and 800H alloys as specified in relevant industry standards:

Alloy	UNS Designation	Spec.	Tensile Strength (psi)	Yield Strength (psi)
800	N08800	B514, B515	75,000 (520 MPa)	30,000 (205 MPa)
800H	N08810	B514, B515	65,000 (450 MPa)	25,000 (170 MPa)

Elongation and Grain Size Requirements Both alloys feature a minimum elongation of 30% over a length of 2 inches, showcasing their ductility. The 800H variant also has a grain size requirement of five or coarser, which ensures optimal mechanical performance.

Hardness and Elasticity While specific hardness values are not provided in the industry standards, these alloys are known for their ability to maintain hardness at elevated temperatures and during service. The modulus of elasticity is approximately 7.9 x 10^6 psi for both alloys, indicating a consistent performance under stress.

Chemical Composition

The composition of Super Austenitic 800 and 800H alloys is vital to their performance characteristics. Below is the detailed composition as required by the industry standards:

Element	800 (N08800)	800H (N08810)
Nickel (Ni)	30.0 – 35.0%	30.0 – 35.0%
Chromium (Cr)	19.0 – 23.0%	19.0 – 23.0%
Iron (Fe)	39.5% Min.	39.5% Min.
Molybdenum (Mo)	—	—
Titanium (Ti)	Max. 0.15 – 0.60%	Max. 0.15 – 0.60%
Carbon (C)	Max. 0.10%	Max. 0.05 – 0.10%
Copper (Cu)	Max. 0.75%	Max. 0.75%
Manganese (Mn)	Max. 1.5%	Max. 1.5%
Sulphur (S)	Max. 0.015%	Max. 0.015%
Silicon (Si)	Max. 1.00%	Max. 1.00%

This composition underscores the emphasis on nickel and chromium to enhance corrosion resistance and strength, particularly in high-temperature environments.

Product Specifications

Super austenitic alloys must adhere to stringent industry specifications to ensure safety, reliability, and performance. The relevant specifications for the alloys include ASTM B514 and ASTM B515, which outline the necessary mechanical properties and chemical composition standards.

Industry Applications Super Austenitic 800 and 800H alloys find extensive applications in industries such as:

• Oil and Gas: Utilized in high-temperature, high-pressure environments, they ensure dependable performance and longevity.
• Chemical Processing: The exceptional corrosion resistance is suited for handling aggressive chemicals.
• Power Generation: Ideal for components that experience thermal cycles and extreme conditions, ensuring operational efficiency.

Conclusion

Super Austenitic 800/800H alloys stand out for their robust mechanical properties, versatile chemical composition, and compliance with industry standards. Their capability to maintain integrity under challenging conditions makes them a preferred choice for many industrial applications. By understanding these alloys’ physical properties and their chemical makeup, engineers and designers can effectively utilize them in critical applications, ensuring safety and performance. The 800 series continues to be a cornerstone in materials science, contributing significantly to advancements in various sectors.

This in-depth knowledge not only aids in selecting the appropriate alloy for specific applications but also highlights the importance of adhering to specifications to uphold quality and reliability in performance.