ISSN: 0090-3973
Page Count: 14

Structure and Property Evaluation of Large-Diameter Spray-Formed Superalloy Piping
Moran, AL
Assistant Professor, United States Naval Academy, MD

Rebis, RE
Survivability, Structures, and Materials Directorate, Carderock Division, Naval Surface Warfare Center, MD

Abstract

A comparative testing evaluation program was conducted to assess the mechanical properties, metallurgical characteristics and fabricability of spray-formed Alloy 625 tubes and subsequently processed piping. Spray-formed preforms were deposited and reduced via pilger rolling or roll extrusion to produce thin-walled piping in diameters of 10.2, 20.3, and 35.6 cm (4, 8, and 14 in. nominal pipe size). Evaluations based on chemical analysis, strength, ductility, hardness, impact toughness, fatigue properties, weldability, and corrosion resistance demonstrated that spray-formed piping appears to be a viable substitute for conventionally produced Alloy 625 piping and that a minimal amount of cold working is required on the as-deposited tubular preforms in order for them to meet the specification requirements for naval applications.

Keywords:
spray forming, large-diameter piping, superalloys, mechanical testing, metallurgical characterization, pilger rolling, roll extrusion, Alloy 625, seawater service

Paper ID: JTE11308J
DOI: 10.1520/JTE11308J
ASTM International is a member of CrossRef.