Microchemical analysis of non-metallic inclusions in C-MN steel shielded metal arc welds by analytical transmission electron microscopy
By: Jon D. Walters
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 143
Description: Microchemical analyses of the inclusions present in several shielded metal-arc steel weld metals were made by      analytical transmission electron microscopy (TEM). Low alloy C-Mn steel weld metal samples were studied in      which only the titanium and aluminum contents varied significantly. Carbon extraction replicas were made from      each of the weldments and the inclusions were analyzed in the TEM by energy dispersive x-ray (EDX) and      parallel electron energy loss spectroscopy (PEELS). The results indicated that, for weld metals containing small      amounts of M (13 ppm), the inclusions were comprised of MnO-SiO2, TiO (maybe as a compound) and      Cu(Mn)S. As the M content was increased to 160 ppm, Mn and Si no longer took part in the deoxidization      process and the inclusion compositions were dominated by TiO and A12O3 along with some sulfides. For      weld metal containing a much higher amount of Al (580 ppm) the inclusions became essentially mixtures of TiO,      Al2O3 and TiN sometimes complexed with sulfides. These inclusion chemistries were predicted by the use of      equilibrium thermodynamics and their effect on the microstructure and mechanical properties of the steel weld      metals investigated.
Notes: "June 1998."

Thesis advisor(s): A.G. Fox.

Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, June 1998.

Includes bibliographical references (p. 139-141)

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat reader.

US Navy (USN) author.

dk/dk cc:9116 10/06/98