Effect of the void and crack quantity and location on ultrasound: resin experiments and carbon brick validation

ABSTRACT

In industrial applications, there is a lack of methods applicable to large-scale, rapid and non-destructive detection of voids and cracks inside carbon bricks. This paper used the ultrasonic testing (UT) A-scan method to investigate the influence of quantity (void fraction:1.4%-4.6%; number of artificial cracks:1–7) and location (five layers) of voids and cracks inside the resin on ultrasonic waves. Both fast Fourier transform (FFT) and synchrosqueezed wavelet transform (SWT) are employed to analyse the amplitude, main frequency and normalised peak time of ultrasonic waves. The results indicate that increased void fraction and number of cracks lead to greater amplitude attenuation, promoting the transition from the fundamental wave to harmonics. Void and crack location symmetrically affect ultrasound amplitude, main frequency, and normalised peak time around the sample centre. Meanwhile, fitting equations are established for the main frequency of the fundamental wave (f₁) in relation to defect quantity. A high-precision quantitative defects detection standard is also developed based on normalised peak time. The validation based on carbon bricks indicates that the derived empirical relations between these parameters and defects can lay the foundation for large-scale and rapid non-destructive detection in carbon bricks.

KEYWORDS:

• Ultrasonic testing (UT)
• carbon bricks
• resin
• quantity
• location

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Authors’ contributions

SY.W. performed experiments and worked on manuscript. MQ.L., DJ.Q. and YD.X. assisted SY.W. with experiments and contributed to manuscript. D.L. and YJ.Z. provides experimental materials and some experimental ideas. H.W and YW.Y. guided the research and revised the manuscript.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51974182], Distinguished professor (Tracking Plan) of Oriental Scholars of Shanghai Universities [grant numberGZ2020013],National 111 Project (The Programof Introducing Talents ofDiscipline to University)[grant number D17002], Independent Research Project of State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of advanced Ferrometallurgy, Shanghai University [grant number SKLASS 2022-Z01], the Science and Technology Commission of ShanghaiMunicipality [grant number 19DZ2270200], China Baowu Low Carbon Metallurgy Innovation Foudation- BWLCF202112 and Ironmaking Plant, Baosteel Branch, Baoshan Iron & Steel Co., Ltd.(Project for optimization of the slagging regime for large blast furnace with economic burden)[grant number Z22BSLT076].