Analisis XRD dan Kekerasan Baja Hadfield setelah Deformasi Cold Rolling

Hadfield steel demonstrates outstanding mechanical characteristics, merging significant work-hardening ability with substantial ductility. This research intends to examine the impact of plastic deformation on Hadfield steel via the cold rolling (CR) technique. The examined samples included both as-cast specimens and those subjected to cold reduction (CR) of 20%, 30%, and 40%. The Hadfield steel specimens were fabricated through casting and later sectioned with wire cutting. The samples were subsequently affixed with resin and hardener, then ground and polished before characterization. X-ray diffraction (XRD) was utilized for phase identification, and the diffraction data were examined with HighScore software to ascertain the existing phases, full width at half maximum (FWHM), and approximations of crystallite size and microstrain through Williamson–Hall analysis. Moreover, Vickers hardness assessment utilizing a 30 kgf load was conducted to analyze alterations in hardness due to plastic deformation occurring during cold rolling. The findings indicated that augmenting the extent of plastic deformation via cold rolling led to a reduction in crystallite size, decreasing from 33.68 nm in the as-cast state to 32.91 nm (CR 20%), 22.28 nm (CR 30%), and 21.61 nm (CR 40%). Conversely, the microstrain escalated from 0.53% in the as-cast state to 0.68% (CR 20%), 0.72% (CR 30%), and 0.92% (CR 40%). The rise in microstrain signifies an escalation in lattice distortion as assessed via XRD peak broadening analysis with heightened plastic deformation. The Vickers hardness measurements indicated a rise in hardness corresponding to the level of deformation, progressing from 212.1 ± 10.2 HV30/10 in the as-cast state to 401.4 ± 6.6 HV30/10 (CR 20%), 469.7 ± 18.4 HV30/10 (CR 30%), and 525.7 ± 56.0 HV30/10 (CR 40%). The noted enhancement in hardness aligns with strain hardening caused by plastic deformation throughout the cold rolling procedure.