کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10292979 511599 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Magnetic Barkhausen emission technique for detecting the overstressing during bending fatigue in case-carburised En36 steel
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
پیش نمایش صفحه اول مقاله
Magnetic Barkhausen emission technique for detecting the overstressing during bending fatigue in case-carburised En36 steel
چکیده انگلیسی
The effect of bending fatigue at different maximum stress levels on the magnetic Barkhausen emission (MBE) has been studied in case-carburised En36 steel specimens. The low frequency MBE profile has been measured after unloading the specimen at different number of fatigue cycles. It has been found that, beyond 1000 MPa, the MBE peak height decreases just after few thousand cycles and the percentage reduction in the MBE peak increases with maximum bending stress level. The reduction in MBE peak at lower stresses (<1400 MPa) is attributed mainly to the effect of residual stresses becoming more compressive below the surface due to the application prior tensile stress. At higher stresses (1500 MPa), the variation in the MBE peak also indicates the effect of cyclic hardening and softening with progressive fatigue cycles. The MBE profiles measured after monotonic loading and unloading with different maximum stress levels also show similar reduction in the MBE peak with increase in pre-stress level. However, at higher stresses (>1400 MPa), the cyclic loading shows larger reduction in the MBE peak than the monotonic loading. This is attributed to the effect of cyclic microplasticity induced enhancement of dislocation density in addition to the residual stress modification. This study clearly shows the MBE technique can be used to detect the maximum stress level seen by the specimen beyond 1000 MPa. Any overstressing of this case-carburised steel beyond the fatigue limit of 1150 MPa can be easily detected from the percentage reduction in the MBE peak. Since the crack propagation stage is insignificant in these hard steels, the detection of any overstressing using the MBE technique would be very useful in assessing and preventing the impending catastrophic failure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NDT & E International - Volume 38, Issue 2, March 2005, Pages 159-166
نویسندگان
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