A precise magnetic flux leakage method for the defects detection within the steel thin sheet

9th International Symposium on Electromagnetic Processing of Materials

材料科学;物理学

Wang, Bo^1 ; Wang, Xiaodong^1

College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Science, Beijing

101408, China^1

关键词: Ferromagnetic steel;    Linear operation range;    Magnetic flux leakage;    Magnetic flux leakage technologies;    Magneto resistive sensors;    Metallurgical industry;    Metallurgical productions;    Steel thin sheets;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/424/1/012010/pdf
DOI  :  10.1088/1757-899X/424/1/012010

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Defects detection of ferromagnetic steel thin sheet is very important in metallurgical industry. In this article, a new magnetic flux leakage (MFL) technology is used to complete this task. In our work, a tiny permanent magnet is used to replace the conventional coils to magnetize testing specimen and precise Tunnel Magneto-resistive (TMR) sensor is employed because of its superior sensitivity and linear operation range over traditional magneto-resistive sensors. Two kinds of thin sheets were selected: galvanized sheet and cold-rolled sheet. The experimental results indicate that the present method is reliable for detecting defects of steel thin sheet, and defects with diameter of 400 and 20 μm can be detected clearly for galvanized sheet and cold-rolled sheet, respectively. This accuracy fully satisfies the metallurgical production requirement. This method exhibits its potential to realize in-situ, online inspection process of thin sheet production.