Modeling of Magnetic Properties of High Strength Steels

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Materials OBJECTIVE: Develop physics-based material models for the understanding and prediction of stress-induced hysteretic magnetic behavior of high strength steels. DESCRIPTION: The problem of stress-induced hysteretic magnetic behavior of high strength steels is challenging and a pressing one for the Navy. This is because Navy vessels, in general, and submarines, in particular, are subjected to stresses and complex changes in magnetic states that in turn causes their magnetic signature to evolve in a nonlinear, hysteretic fashion. Lack of fundamental understanding of this phenomenon prevents the Navy from designing magnetic signature reduction systems using a rigorous physics-based approach. Consequently, the Navy and industry address this issue by resorting to empirical approaches lacking sufficient physics-based understanding. Computationally tractable models have been developed for the hysteretic magnetic behavior of steels of interest [Refs 4,5]. The commercial sector addresses this problem, e.g., for the effect of stresses on steels used in motor stators [Ref 5]. However, these models typically do not investigate the impact on the magnetic behavior due to hysteresis induced by large stresses of the order of 100's of mega Pascals (MPa). This effect is of great interest to the Navy. While investigators have studied the effect of large stresses on hysteretic behavior of steels [Refs 1,2], fundamental understanding of this behavior that can be translated into a robust computational tool is still lacking. Developing a computationally tractable model that accurately captures the physics is challenging because it involves the interplay of structural, stress, and magnetic properties spanning extremely varied length scales [Ref 3]. Therefore, this STTR topic calls for proposals that emphasize the need for a rigorous understanding of the effect of stress on the hysteretic behavior of high strength steels. Research and development are needed for the following inter-dependent areas: 1. Measurement of magneto-elastic and magneto-thermal hysteresis. 2. Development of both fundamental and phenomenological physics-based models of magneto-elastic and magneto-thermal hysteretic behavior based on measurements. 3. Implementation of the developed models into an efficient computational tool for rapid and robust prediction of magnetic behavior. Taken together, the measurements, models, and computational predictions will be assessed against measurements and predictions based on physical scale and simple computational models. PHASE I: Provide a concept of an approach to model the magnetic properties of high strength steels. Ensure that the concept clearly demonstrates how the challenges inherent in the three R&D areas in the Description section above will be addressed. Measure the effectiveness of the feasibility of the concept, e.g., by applying the methodology on idealized and geometrically simple objects such as spheres or shells with magnetically simple properties as test cases to serve as subscale prototypes or surrogates. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. PHASE II: Build on the results obtained in Phase I to make a more robust framework that will consider the measurements and modeling of simple shapes to develop and implement measurement and computational tools that can be applied to a wide variety of magnetic and stressed environments. These measurement and computational tools will also be applied to objects of increasing geometric complexity. The results of the application of the above tools will be verified or validated against comparable results obtained on Navy-owned physical scale models. The results of the verification and validation as well the computational tools (prototype) will be delivered to the Navy. PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the mature computational tool prototype as well as measurement techniques that have been developed in Phase II for use by the Navy. Routinely validate, test, qualify, and certify the tools for Navy use by a rigorous verification and validation process involving comparisons against physical scale model and full-scale measurements. In addition, the computational and measurement tools will be used for the understanding and characterization of commercial steels that are likely to be used for high-stress and low-ambient magnetic field applications. REFERENCES: 1. Schneider, Carl S.; Gedney, Stephen D.; Travers, Mark A.; Gedney, Joseph J.; Netzahualcoyotl Ojeda-Nayala; Redmond, Kyle E. and Gomez, Isabella M. Isotropic Micromagnetic Field Model of Ferromagnetic Stress Effects. Physica B, 666, 2023, 415120. https://doi.org/10.1016/j.physb.2023.415120 2. Schneider, Carl ;S, Gedney, Stephen D.;, Travers, Mark A.; Gedney, Joseph J. and Redmond, Kyle E. Measurement and Gaussian Model of Ferromagnetic Viscosity. Physica B, 635, 2022, 413830. https://doi.org/10.1016/j.physb.2022.413830 3. Hubert, O. Multiscale Magnetoelastic Modeling of Magnetic Materials Including Isotropic Second Order Effect. J. Magn. Magn. Mats., 491, 2019, 165564. https://doi.org/10.1016/j.jmmm.2019.165564 4. Chwastek, Krzysztof and Gozdur, Roman. Towards a unified approach to hysteresis and micromagnetics modeling: A dynamic extension to the Harrison model. Physica B, 572, 2019, pp. 242-246. https://doi.org/10.1016/j.physb.2019.08.016 5. Cui, Ronggao; Li, Shuhui; Wang, Zhe and Wang, Xinke. A modified residual stress dependent Jile-Atherton hysteresis model. J. Magn. Magn. Mats., 465, 2018, pp. 578-584. https://doi.org/10.1016/j.jmmm.2018.06.021 KEYWORDS: Ferromagnetism; Stress; Hysteresis; Isotropic Model; High Strength Steel Measurement; Multi-scale Modeling; Magneto-elastic