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Volume 5, Issue 6 (Suppl) J Mat. Sci.
ISSN: 2321-6212 Advanced Materials 2017
October 26-28, 2017
OCTOBER 26-28, 2017 OSAKA, JAPAN
13TH INTERNATIONAL CONFERENCE ON
Advanced Materials and Nanotechnology
Surface modification of low-alloy steels by a multifunction cavitation
Masataka Ijiri, Daisuke Nakagawa, KumikoTanaka and Toshihiko Yoshimura
Tokyo University of Science, Japan
Alloy steels for machine structural are used for industrial equipment. However, the operating environment is often harsh,
requiring the development and application of various surface treatments. The authors focus on the use of Water Jet
Cavitation (WJC) with ultra-sonication. WJC technology enables the generation of high pressure during cavitation collapse
near the surface when a water jet ejected from a nozzle impacts a metal surface. This pressure causes a slight deformation in
the impacted surface region and introduces a compressive residual stress due to the elastic constraints of the underlying and
surrounding metal. If ultrasonic irradiation is applied to WJC bubbles with diameters of several hundred microns, the bubbles
are subjected to alternating high and low sound pressures which lead to a high-pressure and high-temperature reaction field.
This technique is referred to as Multifunction Cavitation (MFC). In present study, the compressive residual stress and corrosion
resistance of Cr-Mo and Ni-Cr-Mo steels were improved by MFC treatment. Moreover, the authors compared conventional
WJC technology to MFC technology. MFC was found to lead to higher compression residual stresses and higher corrosion
resistances compared to conventional WJC. The corrosion resistance was revealed by the formation of an oxide film through
selective oxidation and the concomitant reduction of surface defects. The oxide coating is formed by a reaction between the
dissolved oxygen in water with Cr on the metal surface during processing.
Biography
Masataka Ijiri has completed his Bachelor of Engineering and Masters in Mechanical and System Engineering. Specialist in Materials Engineering and has
Engineering Doctor's degree at Okayama University.
Masataka Ijiri et al., J Mat. Sci. 2017, 5:6
DOI: 10.4172/2321-6212-C1-009