摘要 : An attempt was made to evaluate nondestructively thermally degraded 2.25Cr-1Mo steel by. magnetic Barkhausen noise (MBN) technique. Microstructural analysis (mean size of carbides), measurement of mechanical property (hardness) an... 展开 An attempt was made to evaluate nondestructively thermally degraded 2.25Cr-1Mo steel by. magnetic Barkhausen noise (MBN) technique. Microstructural analysis (mean size of carbides), measurement of mechanical property (hardness) and magnetic Barkhausen noise parameters (rms voltage, count) for a wide range of specimens isothermally degraded at 630 C were carried out to obtain the correlations between them. Both the rms voltage (MBNrms) and the count (MBNcount) of MBN signal were observed to increase rapidly in the initial 1000 hours of aging time and then slowly thereafter, which was attributed to decreased number of carbides as a result of carbides coarsening during thermal aging. Linear correlations of MBNcount with both the mean size of carbides and the hardness were found. MBNcount was suggested as a promising nondestructive evaluation parameter for assessing the thermally degraded microstructure and mechanical property of the 2.25Cr-1Mo steel. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 收起