Kim Yeonggeun, Kim Jongbeom, Ahn Joongho, Han Moongyu, Lim Hae Gyun, Lee Ki Jong, Lee Juseung, Kim Chulhong, Kim Hyung Ham
Department of Convergence IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si, Gyeongbuk, 37673, Republic of Korea.
Medical Device Innovation Center, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si, Gyeongbuk, 37673, Republic of Korea.
Sci Rep. 2021 Oct 14;11(1):20416. doi: 10.1038/s41598-021-99907-4.
With the increasing need for steel sheet quality assurance, the detection of micro-scaled inclusions in steel sheets has become critical. Many techniques have been explored to detect inclusions, e.g., visual inspection, radiography, magnetic testing, and ultrasound. Among these methods, ultrasound (US) is the most commonly used non-destructive testing (NDT) method due to its ease of use and deep penetration depth. However, ultrasound currently cannot be used for detecting the micro-scaled inclusions due to low spatial resolution, e.g., less than 30 μm, which are the key important factors causing the cracks in the high-quality steel sheets. Here, we demonstrate a high-resolution US imaging (USI) using high-frequency US transducers to image micro inclusions in steel sheets. Our system utilizes through-transmission USI and identifies ultrasound scattering produced by the inclusions. We first ultrasonically imaged the artificial flaws induced by the laser on the steel sheet surface for validating the system. We then imaged the real inclusions in the steel sheets formed during manufacturing processes and analyzed them to derive quantitative parameters related to the number of micro-scaled inclusions. Our results confirm that inclusions less than 30 μm can be identified using our high-resolution USI modality and has the potential to be used as an effective tool for quality assurance of the steel sheets.
随着对钢板质量保证需求的不断增加，检测钢板中的微观夹杂物变得至关重要。人们已经探索了许多检测夹杂物的技术，例如目视检查、射线照相、磁测试和超声波检测。在这些方法中，超声波（US）由于其易于使用和穿透深度深，是最常用的无损检测（NDT）方法。然而，由于空间分辨率低，例如小于30μm，超声波目前不能用于检测微观夹杂物，而这些微观夹杂物是导致高质量钢板出现裂纹的关键重要因素。在此，我们展示了一种使用高频超声换能器对钢板中的微观夹杂物进行成像的高分辨率超声成像（USI）。我们的系统利用穿透式超声成像并识别夹杂物产生的超声散射。我们首先对钢板表面由激光诱导的人工缺陷进行超声成像以验证该系统。然后我们对制造过程中形成的钢板中的实际夹杂物进行成像并对其进行分析，以得出与微观夹杂物数量相关的定量参数。我们的结果证实，使用我们的高分辨率超声成像模式可以识别小于30μm的夹杂物，并且有潜力用作钢板质量保证的有效工具。
