T-Shaped Fillet Weld Testing of 9% Ni Alloy Steel Based on Total Focusing Phased Array Technique

• Published in: Russian journal of nondestructive testing 2022-06, Vol.58 (6), p.444-454
• Main Authors: Dong, Huang Huan, Jie, Qian Sheng, Xiang, Shen Zheng, Du, Wang, Yue, Chen Ding, Qiang, Wang
• Format: Article
• Language: English
• Subjects: Acoustic Methods; Alloy steels; Anisotropy; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystal defects; Flaw detection; Materials Science; Nickel base alloys; Phased arrays; Storage tanks; Structural Materials; T shape; Ultrasonic testing; Wave propagation; Weld tests
• ISSN: 1061-8309; 1608-3385
• DOI: 10.1134/S1061830922060043

The T-shaped weld structure of LNG tank nickel-based alloy is complex and the grain of the weld is coarse and anisotropy. The conventional ultrasonic detection technique cannot effectively detect its internal defects. In this paper, the acoustic model of T-shaped weld was built based on CIVA software, the ultrasonic wave propagation characteristics and defect response in 9% Ni alloy specimen was simulated. Then, the 9% Ni alloy specimen with artificial flaws was designed, and the phased array imaging based on total focusing method was studied using double-sided array. The quantification and localization of artificial defects were successfully detected. Finally, the research results were applied to the engineering project, and the lack of penetration flaw in the T-shaped weld of one large LNG storage tank were successfully detected, which effectively ensuring the safe use of the storage tank.