Work

Micro-focused X-ray diffraction imaging analysis of Fe nitrides and carbides in the compound layer of nitrocarburized and gas nitrided steel surfaces

Year: 2025

Type: article

Abstract: Thermochemical treatments like nitrocarburizing and gas nitriding form hardened surface layers of iron nitrides and carbides, improving wear, fatigue, and corrosion resistance in steel loaded components. This study employs micro-focused X-ray diffraction (µXRD) imaging at synchrotron facilities to characterize the microstructure of nitrocarburized and gas-nitrided steel surfaces in three steel grades (46MnVS3, 34CrNiMo6, 16CrMnNiMo9-5-2). Through line profile analysis with fine-step mesh grid scanning, we spatially resolve phase distributions and elastic/plastic strains in the compound layer. The ε-phase exhibits isotropic residual strain, transitioning from expansion to compression with depth, while the γ ’-phase displays anisotropic strain, expanding perpendicular to the surface and compressing parallel to it. These findings highlight µXRD’s potential for detailed structural analysis, enabling optimization of surface hardening processes.

Source: Materials Today Communications

DOI: 10.1016/j.mtcomm.2025.112950