Use of Alloy 800H as a Heat-Exchanger Material

Authors

Ajit K. Roy, University of Nevada, Las VegasFollow
Vinay Virupaksha, University of Nevada, Las VegasFollow
Jagadesh Yelavarthi, University of Nevada, Las VegasFollow

Document Type

Conference Proceeding

Publication Date

2005

Publication Title

2005 AIChE Annual Meeting and Fall Showcase

Publisher

American Institute of Chemical Engineers

First page number:

7952

Last page number:

7957

Abstract

Identification and characterization of structural materials for high-temperature heat exchangers to be used in nuclear hydrogen generation pose severe challenge to scientists and engineers. However, Alloy 800H has been widely used for high-temperature applications in the presence of hostile environments in view of its superior metallurgical and corrosion properties documented in the published literature (1-5). The tensile properties of Alloy 800 H have been determined at temperatures ranging from ambient to 600°C. The tensile strength of this alloy was gradually reduced with increasing temperature, as expected. However, some reduction in failure strain was noted at temperatures up to 200°C, which can be attributed to the dynamic stain ageing effect. The results of stress-corrosion-cracking (SCC) testing performed in a simulated acidic solution at constant-load (CL) did not exhibit any failure. The magnitude of true failure stress was gradually reduced in SCC testing under a slow-strain-rate (SSR) condition without showing any significant variation in ductility parameters. The localized corrosion study conducted in a similar environment by a polarization technique revealed more active (negative) critical potentials at elevated temperatures. The fractographic evaluations of the tested specimens showed dimpled microstructures indicating ductile failures.

Keywords

Alloy 800H; Alloys – Cracking; Alloys – Fatigue; Alloys – Fracture; Corrosion resistance; Heat exchangers – Materials; High temperatures; Hydrogen as fuel; Nuclear energy; Tensile properties; Fractography; Stress corrosion

Disciplines

Materials Science and Engineering | Mechanical Engineering | Mechanics of Materials | Metallurgy | Oil, Gas, and Energy | Sustainability

Language

English

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Roy, A. K., Virupaksha, V., Yelavarthi, J. (2005). Use of Alloy 800H as a Heat-Exchanger Material. 2005 AIChE Annual Meeting and Fall Showcase 7952-7957. American Institute of Chemical Engineers.