Feasibility of underwater friction stir welding of hardenable alloy steel
Download
Author
Overfield, Norman E.
Date
2010-12Advisor
McNelley, Terry R.
Second Reader
Menon, Sarath
Metadata
Show full item recordAbstract
The objective of this thesis is to determine whether friction stir welding (FSW) is a feasible welding process for steels in an underwater environment. Specific benefits would be underwater weld repairs on steel alloy piping systems and/or structures, and crack repairs on control surfaces of submarines without the need for strict environment controls or in the submarine's case, for drydocking. A single tool made of polycrystaline cubic boron nitride (PCBN) with a Tungsten-Rhenium binder was used to conduct a series of bead-on-plate FSW traverses, approximately 64 inches (1.6 m) in total length, on 0.25 inch (6.4 mm) thick plates of a hardenable alloy steel. The first series of traverses involved various revolutions per minute (RPM) and inches per minute (IPM) combinations on a dry plate. A second series was conducted while a plate was immersed in water in order to assess the potential for inducing hydrogen assisted cracking (HAC) during FSW of susceptible alloys. All traverses were visually defect-free. The FSW nuggets (stir zone) exhibited refined microstructures and increased hardness relative to the base plate. Based on preliminary findings, FSW of hardenable alloy steel is a feasible process and should be further researched and refined.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
Applications of Arbitrary Lagrangian-Eulerian (ALE) analysis approach to underwater and air explosion problems
Trevino, Theodore (Monterey, California. Naval Postgraduate School, 2000-09);A series of underwater and air explosion investigations was conducted using the Arbitrary Lagrangian-Eulerian (ALE) numerical technique. The investigation primarily examined the explosive-fluid, fluid-structure, and fluid-air ... -
Underwater welding in the deep sea.
Erickson, David Paul (Massachusetts Institute of Technology, 1978-05);A summary of underwater welding methods presently in use or under development are reviewed in order to determine which methods have possible application to deep sea use (depths greater than 1000 feet). Studies on one of ... -
Nonlinear Response of Cylindrical Shells to Underwater Explosion: Testings and Numerical Prediction Using USA/DYNA3D / June 1, 1991 - March 1, 1992
Fox, P. K.; Kwon, Y. W.; Shin, Y. S. (Monterey, California: Naval Postgraduate School., 1992-03); NPS-ME-92-002Nonlinear 3-D Dynamic Analysis Code (VEC/DYNA3D) has been interfaced with Underwater Shock Analysis Code (USA) and capabilities were developed to perform numerical analysis of submerged and semi-submerged marine structures ...