Interfacial Strength Evaluation of Oxide Films on Carbon Steel by Using the Laser Shock Adhesion Test

Journal Article · Thu Aug 15 00:00:00 EDT 2019 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-019-04246-1· OSTI ID:22970540

Saito, Yusaku; Watanabe, Hiroki; Yamada, Takeshi; Kanamori, Kohei; Yonezu, Akio ^[1]

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1. Chuo University, Department of Precision Mechanics (Japan)

We investigate the adhesion strength (interfacial strength) of the oxide film formed on a carbon steel substrate by using a laser shock adhesion test (LaSAT). A rolled carbon steel (SS400) plate is first heated at high temperature (700 °C) under the atmosphere (heat treatment) to cause the formation of oxide films about 20-50 μm thick on the steel surface. The film consisted of multiple layers, including wustite (FeO), magnetite (Fe{sub 3}O{sub 4}), and hematite (Fe{sub 2}O{sub 3}). Next, the x-ray diffraction method was used to measure the residual stress in the film. We find that compression stress develops in the film because of a mismatch of thermal strain in between the film and substrate after the heat treatment. With LaSAT, strong elastic wave generates by a pulsed laser ablation of the substrate backside, and results in interfacial fractures in the oxide films. To monitor the normal (out-of-plane) displacement of the top surface film, a laser ultrasonic interferometer is simultaneously utilized, such that we detect film delamination and determine the critical laser energy for interfacial fracture to obtain the critical stress (interfacial strength). Furthermore, additional pulsed laser irradiation is conducted against a pre-delaminated specimen in order to examine the growth of delamination area and evaluate the interfacial fracture toughness. Finally, elastic wave propagation in the sample is computed using the finite element method (FEM) in order to evaluate the interfacial stress field, accurately. For the FEM, multiple layers in the oxide film are modeled, and the residual stress due to thermal strain mismatch is introduced. The FEM computations reveal the stress distribution around the interface and evaluate the critical stress and critical stress intensity factor for delamination. We thus quantitatively evaluate the interfacial strength and interfacial fracture toughness of the oxide film formed on carbon steel. The mechanism of interfacial fracture is also discussed on the basis of microstructures in a film with multiple layers. This result may be useful for understanding the adhesion quality of oxide film during the hot-rolling process.

• OSTI ID: 22970540
• Journal Information: Journal of Materials Engineering and Performance, Vol. 28, Issue 8; Other Information: Copyright (c) 2019 ASM International; Country of input: International Atomic Energy Agency (IAEA); ISSN 1059-9495
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADHESION
CARBON STEELS
CRYSTAL GROWTH
CRYSTAL LATTICES
EVALUATION
FERRITES
FILMS
FINITE ELEMENT METHOD
FRACTURE PROPERTIES
HEAT TREATMENTS
IRON OXIDES
LASER RADIATION
OXIDATION
RESIDUAL STRESSES
STRESS INTENSITY FACTORS
SUBSTRATES
ULTRASONIC WAVES
WAVE PROPAGATION
X-RAY DIFFRACTION