Manufacturing Inspection of Electrical Steels using Magnetic Barkhausen Noise: Residual Stress Detection

摘要

Non-oriented Electrical Steel (NOES) is the magnetic core laminationmaterial used for flux transfer in rotary machines. The presence of residualstress associated with material processing may be detrimental to magneticdomain structure refinement and as a result, magnetic performance of NOES.Therefore, manufacturing inspection of NOES that identifies the presence ofresidual stress could contribute to the production of more energy efficientcores. However, standard materials evaluation is limited to destructive andoff-line techniques. The present work employed Magnetic Barkhausen Noise(MBN) for nondestructive identification of local residual stress associated withstages in material processing. Analysis of MBN from single strips of NOESdemonstrated clear response to applied tensile stress, mechanical shearing,the presence of an insulating coating and punching. The results establish thepotential of MBN as a nondestructive testing technology for quality control ofelectrical steels at various stages of manufacture.