Advanced Characterization Techniques for Quantifying and Modeling Deformation: On-Demand Oral Presentations
Sponsored by: TMS Extraction and Processing Division, TMS Structural Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Materials Characterization Committee
Program Organizers: Arul Kumar Mariyappan, Los Alamos National Laboratory; Irene Beyerlein, University of California, Santa Barbara; Wolfgang Pantleon, Technical University of Denmark; C. Tasan, Massachusetts Institute of Technology; Olivia Underwood Jackson, Sandia National Laboratories
Monday 8:00 AM
March 14, 2022
Room: Characterization
Location: On-Demand Room
Characterization of Heat-resistant Steels and Alloys for Life-prediction Modeling: Yukinori Yamamoto1; David Hoelzer1; Michael Lance1; Michael Brady1; Edgar Lara-Curzio1; Qing-Qiang Ren2; Jonathan Poplawsky2; Arul Kumar Mariyappan3; Ricardo Lebensohn3; Laurent Capolungo3; Michael Glazoff4; Michael Gao5; Paul Jablonski5; Jeffrey Hawk5; 1MSTD, Oak Ridge National Laboratory; 2CNMS, Oak Ridge National Laboratory; 3Los Alamos National Laboratory; 4Idaho National Laboratory; 5National Energy Technologies Laboratory
A multi-national laboratory project to establish the accelerated methods for designing and developing high-temperature structural alloys for “extreme environments” is currently underway. One key element of this project involves the fabrication of model alloys (347H stainless steels and alumina-forming austenitic steels) with a reliable pedigree, their evaluation through isothermal aging and uni- and multi-axial creep tests to monitor their response as a function of temperature and stress, and then correlating the results from these tests with microstructure through multi-scale characterization using SEM, TEM, XRD, and APT. The results from these activities are being used to support the formulation and validation of newly developed, physics-based life-prediction modeling of precipitation-strengthening heat-resistant steels and alloys, which will also be presented. Research sponsored by the U.S. DOE, Office of Fossil Energy and Carbon Management, the Crosscutting Technology High Performance Materials Research Program. ORNL’s CNMS, a DOE-Office of Science user facility is also acknowledged.
3D Orientation and Strain Mapping of Recrystallization and Micro-texture Development in Heavily Deformed Ferritic Alloys: Can Yildirim1; Carsten Detlefs1; Henning Poulsen2; Raquel Rodrigues-Lamas1; Philip Cook1; Mustafacan Kutsal1; Melanie Gauvin3; Dominique Mangelinck4; Myriam Dumont4; Nikolas Mavrikakis3; 1European Synchrotron Radiation Facility; 2Technical University of Denmark; 3OCAS; 4Aix Marseille Universite
We present a multiscale study on the recrystallization annealing of heavily cold rolled (true strain of 2) Fe-Si-Sn alloys using dark field X-ray microscopy, 3D X-ray diffraction (3DXRD) and electron backscattered diffraction (EBSD). A grain oriented along the rolling direction and embedded in a 200-micron thick sample is studied at consecutive annealing steps. The 3D intra-granular structure of the as-deformed grain reveals deformation bands separated by ~ 5° misorientation. An orientation spread > 10° is observed within the grain prior to annealing. During the early stages of annealing, cells having 2-5° misorientation are formed within the deformed grain while the nucleation of the recrystallized grains is observed. The recrystallized grains form at the prior grain boundaries, between the parent and adjacent grains with an internal angular spread around 0.04°. They exhibit no particular orientation relationship with respect to the parent grain. No macroscopic texture change is observed upon further annealing.
Crystal Plasticity Finite Element Simulation of Microstructural Deformation in Ultra-thin Ferritic Steel Sheet: Minh Tien Tran1; Tri Hoang Nguyen1; Sun-Kwang Hwang2; Ho Won Lee3; Dong-Kyu Kim1; 1University of Ulsan; 2Korea Institute of Industrial Technology; 3Korea Institute of Materials Science
In the present study, the effect of subsurface grain orientation on the strain localization in the ultra-thin (≤0.1 mm) ferritic steel sheet is investigated by means of in-situ electron backscatter diffraction (EBSD) technique and crystal plasticity finite element method (CPFEM). Microstructure evolution during uniaxial tensile deformation is monitored by the in-situ EBSD technique. The CPFE simulation is performed using the representative volume element (RVE) obtained by directly mapping EBSD data of the initial microstructure onto the FE mesh. The simulation can capture the inhomogeneous stress/strain distribution and the local hot spots of the ductile fracture initiation in terms of damage criterion and stress triaxiality. Furthermore, the plastic strain localization behavior is discussed based on the kinematic stability of crystallographic orientation to account for the failure in the ultra-thin ferritic steel sheet.
Evolution of Sigma Phases in 347H Stainless Steels Subjected to Isothermal Aging at 750 oC: Qing-Qiang Ren1; Yukinori Yamamoto1; Michael Brady1; Jonathan Poplawsky1; 1Oak Ridge National Laboratory
Sigma phase is an intermetallic compound commonly found in stainless steels after long-term services at elevated temperatures, which damages both mechanical properties and corrosion resistance. We performed SEM, FIB, and APT characterization to identify the sigma phase composition and size evolution in 347H stainless steels for up to 10,000 h aging at 750 oC. The results show that the sigma phase nucleates after ~336h and continues to grow. The sigma compositions at different aging time show little difference in the major elements (Cr and Fe); however, the C concentration decreases from ~0.14 at.% after 336h aging to ~0.05 at.% after >1008h aging. The compositional evolution also reveals the growth mode of sigma phase, which sheds lights on how it can be avoided. APT was performed at ORNL’s CNMS, a US DOE office of science user facility. Research sponsored by US DOE, Office of Fossil Energy and Carbon Management eXtremeMAT program.
An Atomistic-to-microscale Computational Analysis of the Dislocation-interface Reaction and the Subsequent Structure Changes in Two-phase Materials under Compression and Shear: Liming Xiong1; 1Iowa State University
Taking a two-phase material under compression and shear as a model system, here we perform an atomistic-to-microscale computational analysis on how a dislocations pileup is formed at the interface and how it contributes to the subsequent structure changes, such as twinning and phase transformations (PTs), through concurrent atomistic-continuum simulations. One main novelty of this work is a simultaneous resolution of the μm-level dislocation slip, the internal stress complexity, the atomic-level step formation, twinning/PT nucleation and growth near the slip-interface intersection all in one model. The dislocation pileup-induced local stress concentration is found to dictate the subsequent structure evolution: (a) a simultaneous occurrence of twinning and PTs; and (c) a 60% reduction of the PT pressure when tens of dislocations are piled up at the buried interface. The gained knowledge may find applications in understanding the dislocation slip, twinning, PTs and their interaction in many advanced alloys under plastic deformation.