Correlative cross-sectional characterization of nitrided, carburized and shot-peened steels: synchrotron micro-X-ray diffraction analysis of stress, microstructure and phase gradients

Mechanical properties of case modified steels depend decisively on the near-surface gradients residual stresses, microstructures, phases and chemical composition, which are generated by empirically well-established case-hardening techniques. Currently, however, to obtain correlation between structure–property gradients, applied hardening process parameters steels’ overall performance is a very challenging task. In this work, high-energy synchrotron cross-sectional X-ray diffraction (CSmicroXRD) using pencil beam cross-section 20 × 500 ?m2 complementary analytical techniques used characterize surface-to-bulk gradient (i) plasma nitrided steel W300, (ii) carburized (grade 18CrNiMo7-6) (iii) shot-peened high strength steel, type 300M. CSmicroXRD analysis reveals complex martensite austenite phases, stresses in both crystallographic texture evolution peak broadening with spatial resolution ~20 ?m. These correlated hardness, morphology-microstructure changes N C concentrations and/or retained formation/depletion all three model samples. Finally, correlative micro-analytics approach indicates complexity near surface structure-property relationships as well importance innovative characterization, allows for assessing gradual physical accompanying thermo-chemical mechanical treatments.