Affiliations: [a] College of Architecture and Environment, Sichuan University, Chengdu, Sichuan, China | [b] Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang, Sichuan, China
Correspondence:
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Corresponding author: Yunfei Li, Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang, Sichuan, China. E-mail:[email protected]
Abstract: Metal magnetic memory (MMM) technique can be potentially
applied to evaluate early damage of ferromagnetic materials nondestructively
due to its high sensitivity to stress-strain state. An experimental
investigation of the characterizations of mechanical damage-induced
magnetization in X80 pipeline steel specimens has been undertaken. Different
degrees of plastic deformation are introduced into specimens with different
initial discontinuities. The surface strain distribution and metal magnetic
memory signal in specimens are measured during and after tensile testing.
The experimental results indicate that, at first the magnetization direction
of material depends on the loading direction and the distribution pattern of
magnetization reflects the existence of stress concentration. Second, the
correlation between peak-valley amplitude of memory signal B_Z and
maximum plastic deformation follows a similar formula proposed in this
paper, which is independent of specimen type. The results of present work
could potentially be used to quantitatively evaluate the degree of stress
concentration of X80 pipeline steel components.
Keywords: X80 steel, damage-induced magnetization, metal magnetic memory, plastic deformation, nondestructive evaluation
