TY - JOUR
T1 - In-situ observation in a scanning electron microscope on the exfoliation behavior of galvannealed Zn-Fe coating layers
AU - Lee, Kyung Keun
AU - Lee, In Hwan
AU - Lee, Cheul Ro
AU - Ahn, Haeng Keun
N1 - Funding Information:
This work was supported by grant No. R05-2001-000-00831-0 from the Basic Research Program of the Korea Science and Engineering Foundation.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007/2/4
Y1 - 2007/2/4
N2 - Exfoliation behavior of galvannealed (GA) coating layers was continuously observed in-situ under 3-point bending load in a scanning electron microscope (SEM). Two kinds of substrate, Al-killed steel and Ti-stabilized interstitial free (IF) steel, were used. For GA coating layers formed on Al-killed steel, powdering was dominant at the region under compressive stress during the bending. Exfoliation occurred at the Γ/δ1 interface, and the amount of exfoliation decreased with an increase in Fe content in the coating layer. Meanwhile, for GA layers coated on IF steel substrate, flaking was dominant. One of the perpendicular cracks that were pre-induced during galvannealing grew and propagated up to the Γ/Fe matrix interface with increasing strain. On the other hand, the crack initiated at the Γ/Fe matrix interface grew and propagated along the interface. Then, this crack combined with a nearby perpendicular crack, resulted in flaking.
AB - Exfoliation behavior of galvannealed (GA) coating layers was continuously observed in-situ under 3-point bending load in a scanning electron microscope (SEM). Two kinds of substrate, Al-killed steel and Ti-stabilized interstitial free (IF) steel, were used. For GA coating layers formed on Al-killed steel, powdering was dominant at the region under compressive stress during the bending. Exfoliation occurred at the Γ/δ1 interface, and the amount of exfoliation decreased with an increase in Fe content in the coating layer. Meanwhile, for GA layers coated on IF steel substrate, flaking was dominant. One of the perpendicular cracks that were pre-induced during galvannealing grew and propagated up to the Γ/Fe matrix interface with increasing strain. On the other hand, the crack initiated at the Γ/Fe matrix interface grew and propagated along the interface. Then, this crack combined with a nearby perpendicular crack, resulted in flaking.
KW - C. Hot dip
KW - D. Multilayer
KW - D. Zinc alloy
KW - X. Exfoliation
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U2 - 10.1016/j.surfcoat.2006.11.021
DO - 10.1016/j.surfcoat.2006.11.021
M3 - Article
AN - SCOPUS:33847045516
VL - 201
SP - 6261
EP - 6266
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
IS - 14
ER -