The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adem.202200384.

Micromagnetic non-destructive (NDT) methods offer a great potential for the analysis of near-surface properties after machining due to potential time and cost reduction as well as the option to be implemented into the machining process. As a result, the development of soft sensor concepts including micromagnetic NDT methods is in focus of current investigations in order to eventually improve the surface integrity of machined components and, thus, service life and reliability. However, a preceding calibration based on empirical data as well as a reliable validation is often referred to as one of the main challenges of micromagnetic NDT methods. The present study provides insights into the calibration and validation of a micromagnetic 3MA-II system for NDT analysis of the near-surface properties, with a focus on the residual stress depth profiles after hard turning of 51CrV4 specimens. Different calibration functions as well as a combination of different NDT methods are taken into consideration. The results and the potential of the 3MA system as well as open challenges are critically discussed.

The complex thermal history imposed by the laser-based powder bed fusion of metals (PBF-LB/M) process is known to promote the evolution of unique microstructures. In the present study, metastable CrMnNi steels with different nickel contents and, thus, different phase stabilities are manufactured by PBF-LB/M. Results clearly reveal that an adequate choice of materials will allow to tailor mechanical properties as well as residual stress states in the as-built material to eventually redundantize any thermal post-treatment. The chemical differences lead to different phase constitutions in as-built conditions and, thus, affect microstructure evolution and elementary deformation mechanisms upon deformation, i.e., twinning and martensitic transformation. Such alloys designed for additive manufacturing (AM) highlight the possibility to tackle well-known challenges in AM such as limited damage tolerance, porosity and detrimental residual stress states without conducting any post treatments, e.g., stress relieve and hot isostatic pressing. From the perspective of robust design of AM components, indeed it seems to be a very effective approach to adapt the material to the process characteristics of AM.

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In laser‐based direct energy deposition (DED‐LB) additive manufacturing (AM), wire or powder materials are melted by a high‐power laser beam. Process‐specific characteristics enable robust in situ fabrication of compositionally graded materials, e.g., through an adaption of powder mass flow from independent hoppers. Based on the high flexibility of this approach, pathways toward multimaterial AM have been unlocked. Obviously, such characteristics enable high‐throughput alloy development. However, rapid alloy development demands substantial characterization efforts to assess phase and microstructural evolution. So far, property analysis is considered as the limiting factor for these high‐throughput approaches. Herein, the use of high‐brilliance X‐Ray analysis and subsequent micropillar compression testing are introduced to tackle these challenges. As a proof of concept, their application to a compositionally graded material made from AISI 316L stainless steel and a CoCrMo alloy is presented. The results obtained reveal that X‐Ray analysis can be exploited to evaluate process robustness, chemical characteristics, and phase composition within the gradient regions. Moreover, the use of micropillar compression testing provides spatially resolved insights into the mechanical properties of the gradient regions. The combination of both characterization techniques eventually opens pathways toward a robust and time‐efficient alloy development using powder‐fed DED‐LB (DED‐LB/P).

Corrigendum to T. Wegener, A. Liehr, A. Bolender, S. Degener, F. Wittich, A. Kroll, T. Niendorf: Calibration and Validation of Micromagnetic Data for Non-Destructive Analysis of Near-Surface Properties after Hard Turning. HTM J. Heat Treatm. Mat. 77 (2022) 2, pp. 156-172, DOI:10.1515/htm-2021-0023.

Quenching and partitioning (Q&P) steels are characterized by an excellent combination of strength and ductility, opening up great potentials for advanced lightweight components. The Q&P treatment results in microstructures with a martensitic matrix being responsible for increased strength whereas interstitially enriched metastable retained austenite (RA) contributes to excellent ductility. Herein, a comprehensive experimental characterization of microstructure evolution and austenite stability is carried out on a 42CrSi steel being subjected to different Q&P treatments. The microstructure of both conditions is characterized by scanning electron microscopy as well as X‐ray diffraction (XRD) phase analysis. Besides macroscopic standard tensile tests, RA evolution under tensile loading is investigated by in situ XRD using synchrotron and laboratory methods. As a result of different quenching temperatures, the two conditions considered are characterized by different RA contents and morphologies, resulting in different strain hardening behaviors as well as strength and ductility values under tensile loading. In situ synchrotron measurements show differences in the transformation kinetics being rationalized by the different morphologies of the RA. Eventually, the evolution of the phase specific stresses can be explained by the well‐known Masing model.

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