AGMA 07FTM06 PDF

The use of magnetic Barkhausen Noise Analysis (BNA) has been proven to be an effective tool for the non-destructive detection of microstructural anomalies in ferrous materials. Used as an in-process tool for the detection of grinding burn, heat treat defects and stresses, BNA is a quick comparative and quantitative alternative to traditional destructive methods. This paper presents examples that demonstrate how BNA is used to evaluate changes in microstructual properties. Quantitative results correlate BNA test values to X-Ray diffraction values for the detection of changes in residual stress. Qualitative results correlate BNA test values to acid etch patterns/colors for the detection of grinding burn defects.