Microstructure and fracture behavior of ASTM 572 Grade 65 steels used for wind tower applications have been studied. Steels of two carbon level chemistries designed for this grade were used in the study. Fracture toughness of the steels was studied using 3-point bend test on samples coated with zinc and not coated with zinc. Lower carbon steel showed higher resistance to fracture than medium carbon steel after zinc galvanization. SEM study suggests that zinc and zinc bath additives that migrated to crack tips are responsible for the loss in ductility. The phenomenon of Liquid Metal Embrittlement (LME) is suggested to have taken place. Zinc bath additives traced at crack zones are suggested to have migrated at the zinc galvanizing temperatures.
I. C. Okafor et al., "Effect of Zinc Galvanization on the Microstructure and Fracture Behavior of Low and Medium Carbon Structural Steels," Engineering, vol. 5, no. 8, pp. 656-666, Scientific Research Publishing Inc. (SCIRP), Aug 2013.
The definitive version is available at http://dx.doi.org/10.4236/eng.2013.58079
Materials Science and Engineering
Keywords and Phrases
Galvanized Steel; Liquid Metal Embrittlement; Microstructure; Elemental Mapping; Fracture Resistance
International Standard Serial Number (ISSN)
Article - Journal
© 2013 Scientific Research Publishing Inc. (SCIRP)