1988 Fiscal Year Final Research Report Summary
Non-destructive Evaluation of Surface Processing Layer by Using Spectroscopy of Ultrasonic Backscattering
| Project/Area Number |
62850125
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
OBATA Mitsuo Professor Dept. of Materials Processing, Faculty of Engineering, Tohoku University, 工学部, 教授 (10005548)
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| Co-Investigator(Kenkyū-buntansha) |
中居 則彦 (株)日本高周波鋼業, 開発部, 執務員
MIHARA Tsuyoshi Research Assistant, Dept. of Materials Processing Faculty of Engineering, Tohoku, 工学部, 助手 (20174112)
NAKAI Norihiko On leave from Nippon Koshuha Steel
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| Project Period (FY) |
1987 – 1988
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| Keywords | Ultrasonics / Rayleigh Wave / Backscattering / Non-Destructive-Evaluation / Carburize / Spectrum Analysis / 実効値 |
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| Research Abstract |
The purpose of this research is to develop the non-destructive method for evaluating depth of industrial processing layer on specimen surface by using ultrasonic backscattering. For this purpose, we make following three investigations. First is a construction of experimental set-up for measureing backscattering signal. As to the ultrasonic transmission mode, rayleigh wave by using wedge method is abopted as the most superior mode for this research. validity of backscattering signal obtained from these set-up is also confirmed with model samples.
Secondly, since the ordinary backscattering method with signal aceraging procedure take too long measuring time for applying this method to industrial structures, new analytical procedure to shortenthe mesuring time is required. In this research, effective value of power spectrum obtained by FFT analysis for backscattering signalis employed as the parameter for analizing the backscattering signal in a short time. Then the utility of this parameter for the evaluation of depth of processing layer is discussed. Lately, above mentioned experimental set-up and procedures are applied to carburised steels and the depth of these carburised case are evaluated. Then, the effective value of backscattering signal of rayleigh decrease tith the increase of the depth of carburized case. Using these relations, depth of carburized case can be ebaluated by backscattering of rayleigh wave.
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