Effect of tensile deformation on micromagnetic parameters in 0.2% carbon steel and 2.25Cr–1Mo steel

✍ Scribed by V Moorthy; S Vaidyanathan; T Jayakumar; Baldev Raj; B.P Kashyap

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 522 KB
• Volume: 47
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(99)00048-8

✦ Synopsis

AbstractÐThe in¯uence of prior tensile deformation on the magnetic Barkhausen emission (MBE) and the hysteresis (B±H) curve has been studied in 0.2% carbon steel and 2.25Cr±1Mo steel under dierent tempered conditions. This study shows that the micromagnetic parameters can be used to identify the four stages of deformation, namely (i) perfectly elastic, (ii) microplastic yielding, (iii) macroyielding and (iv) progressive plastic deformation. However, it is observed that the MBE pro®le shows more distinct changes at dierent stages of tensile deformation than the hysteresis curve. It has been established that the beginning of microplastic yielding and macroyielding can be identi®ed from the MBE pro®le which is not possible from the stress±strain plot. The onset of microplastic yielding can be identi®ed from the decrease in the MBE peak height. The macroyielding can be identi®ed from the merging of the initially present two-peak MBE pro®le into a single central peak with relatively higher peak height and narrow pro®le width. The dierence between the variation of MBE and hysteresis curve parameters with strain beyond macroyielding indicates the dierence in the deformation state of the surface and bulk of the sample.