Additive Manufacturing of Large-scale Metallic Components: Steels
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee
Program Organizers: Sougata Roy, Iowa State University; Sneha Prabha Narra, Carnegie Mellon University; Andrzej Nycz, Oak Ridge National Laboratory; Yousub Lee, Oak Ridge National Laboratory; Chantal Sudbrack, National Energy Technology Laboratory; Albert To, University of Pittsburgh; Yashwanth Bandari, AddiTec Technologies LLC

Tuesday 2:30 PM
March 21, 2023
Room: 24A
Location: SDCC

Session Chair: Sougata Roy, University of North Dakota; Andrzej Nycz, Oak Ridge National Laboratory


2:30 PM  
Assessment of As-printed Performance in Wire-Arc Additively Manufactured 410NiMo Steel Components: Yukinori Yamamoto1; Wei Tang1; Andres Marquez Rossy1; Andrzej Nycz1; Josh Vaughan1; Donovan Leonard1; Luke Meyer1; Derek Vaughan1; Yousub Lee1; Paul Beckman2; 1Oak Ridge National Laboratory; 2Carl Zeiss Industrial Metrology, LLC
    The microstructural and mechanical responses of wire-arc additively manufactured (WAAM) 410NiMo ferritic-martensitic stainless steel (ER410NiMo, AWS-5.9) to various print conditions have been systematically investigated. 410NiMo was selected as a model case of “highly-alloyed”, “phase transformation-involved” ferrous alloys which could be a basis of various Fe-base materials of interest for industrial use, such as precipitation-hardening steels or tool steels. By considering a complicated shape component production through WAAM, multiple walls were printed with three different inter-pass temperatures (150, 300, and 500°C) and wall thicknesses (2-, 4-, and 8-beads), which were subjected to cross-sectional microstructure characterization with 2D hardness measurement, defect distribution analysis by high-energy x-ray tomography, and tensile/fatigue property evaluation. The results indicated that low inter-pass temperature combining with large wall thickness would result in a variation of mechanical properties attributed to inhomogeneous microstructure evolution as well as internal defect/inclusion formation. Detailed correlation with the process parameters will be further discussed.

2:50 PM  
Mechanical Properties and Fatigue Performance of a Wire Arc Additive Manufactured ER100S-G Steel for HY-80 Applications: Garrett Webster1; Kathleen Chou2; Riyanka Ribble2; Ajay Krishnamurthy2; Shahab Zekriardehani2; Joseph Lawrence1; Meysam Haghshenas1; 1University of Toledo; 2Eaton Corporation
    HY-80 is a quenched and tempered high-strength low-alloy steel with fine-grained bainite and martensite microstructure along with great formability, weldability, and corrosion resistance. Considering various limitations associated with conventional fabrication of large-size structures out of HY-80, this study assesses large format additive manufacturing (e.g., wire arc additive manufacturing) using high strength low alloy wire feedstock (AWS ER100S-G) to potentially be a replacement for conventional manufacturing (e.g., casting/forging). To this end, this research provides microstructure/mechanical property/fatigue performance/process (i.e., WAAM) correlation of the studied ER100S-G steel. The microstructure (optical and scanning electron microscopies), mechanical properties (tensile tests, hardness distribution measurements), and fully-reversed (R= -1) fatigue performance (S-N data) of a wire arc additive manufactured ER100S-G steel are quantified. Also, to quantify the controlling mechanism of fatigue crack initiation (e.g., WAAM-produced defects) and fatigue crack growth pattern, extensive scanning electron microscopy-based fractography assessments was conducted on the fracture surface of the broken specimens.

3:10 PM  
Quantifying the Influence of Plastic Anisotropy on the Prediction of Residual Stress and Distortion of Large Scale Additively Manufactured 316L Stainless Steel: Jason Mayeur1; Yousub Lee1; Yukinori Yamamoto1; Andrzej Nycz1; 1Oak Ridge National Laboratory
    Accurate modeling of residual stress and distortion in additive manufacturing processes is important for predicting part quality and process optimization. In this study, we use crystal plasticity simulations to calculate parameters for an anisotropic and temperature-dependent yield surface for 316L SS produced by the wire + arc additive process. Materials produced by this process have large grain structures and sharp crystallographic textures, which leads to a spatially fluctuating and anisotropic mechanical response throughout the part. This anisotropy is not typically accounted for in thermo-mechanical process models. The crystal plasticity model is used to generate the data for fitting of the macroscale yield surface parameters through computational homogenization. Process model simulations are carried out using the anisotropic plasticity model and residual stress and distortion predictions are compared to those obtained using an isotropic and spatially homogeneous plasticity model.

3:30 PM  Invited
Large Scale Metal Additive Manufacturing – Towards Qualification and Certification: Sudarsanam Babu1; Obed Acevedo1; Andrzej Nycz2; Yukinori Yamamoto2; 1University of Tennessee, Knoxville; 2Oak Ridge National Laboratory
    Large scale metal additive manufacturing provides a pathway to solve the supply chain issues related to high performance metals and alloys processed by traditional manufacturing routes like casting and forgings. Due to the inherent nature of layer-by-layer deposition, it is also possible to transition from one alloy to impart site specific properties for wide range of industrial applications. However, the qualification of these parts remains as a challenge due to familiar issues including defects, residual stress, distortion, heterogeneous microstructure, and properties. In this talk, approaches to meet these challenges based on existing welding literature will be outlined with case studies to produce stamping dies. In this case study, dissimilar metal joint between mild steel and martensitic steel was produced and the interface characteristics were analyzed using thermomechanical simulator. Based on these data, future directions to develop qualify materials as you deposit by coupling modeling and in-situ sensing will be outlined.

4:00 PM Break

4:20 PM  
The Effect of Build Platform Temperature and Thermal Post-Processing on the Ferritic/Martensitic T-91 Stainless Steel Additively Manufactured via Directed Energy Deposition Laser technique: Shmuel Samuha1; Jeff Bickel1; Tuhin Mukherjee2; Tarasankar DebRoy2; Thomas Lienert3; Stuart Maloy4; Calvin Lear4; Peter Hosemann1; 1University of California - Berkeley; 2The Pennsylvania State University; 3Optomec; 4Los Alamos National Laboratory
     The Ferritic/Martensitic T91 steel, a structural material used for various nuclear applications, was fabricated using the directed energy deposition laser technique. Aimed at linking fabrication to performance via defining the process-structure-property relationships, this talk will address two essential issues in the fabrication strategy: 1) the influence of the platform temperature and 2) the effects of a post-processing thermal treatment on mechanical properties and microstructure. Samples machined along the principal axis of a cuboid shape product were evaluated in their pristine state and following different heat treatments. Variations in the mechanical properties were explained in terms of several competing strengthening mechanisms, and their activity was considered owing to fabrication-related mechanisms. Cases showing high potential applicability were further considered a profitable starting point for the design of optimized thermal post-processing treatment.

4:40 PM  
Unique Aspects of Structure-Properties Relationships within Large-scale Structural Components of Fusion Additively Manufactured Stainless Steels: Saket Thapliyal1; Patxi Fernandez-Zelaia1; Andres Rossy1; Quinn Campbell1; Michael Kirka1; Rangasayee Kannan1; Andrzej Nycz1; Anand Kulkarni2; Kyle Stoodt2; 1Oak Ridge National Laboratory; 2Siemens Energy Inc.
    Due to its large-scale manufacturing capabilities, the multiphysics involved in wire arc additive manufacturing (WAAM) differs from the multiphysics in its laser-based fusion additive manufacturing counterparts. Subsequently, the resulting chemistry-processing-structure-properties relationships evolve differently in WAAM. To this end, the solidification behavior, microstructural and mechanical behavior of WAAM-processed stainless steels is investigated with examples of 17-4 precipitation hardenable (PH) and stainless steel 316L. Correlations between process thermokinetics, segregation behaviors of alloying elements, phase stability, microstructural hierarchy, and mechanical behavior are established. Furthermore, the effect of heat treatment on phase stability, precipitation hardening and resulting mechanical behavior is discussed. Implications of microstructural metastability for room and elevated temperature mechanical behavior are also highlighted. Microstructural attributes like sharp crystallographic texture is compelling for several structural applications. Insights on evolution of a few such microstructural attributes in WAAM processed stainless steels are provided. This work opens the pathway for microstructural design and application-specific manufacture of large-scale structural components of stainless steels with WAAM.

5:00 PM  
Wire + Arc Additive Manufacturing of Functionally -graded HSLA and Austenitic Stainless Steel Bi-material Structures: Jose Luis Galan Argumedo1; Mahdi Mahmoudiniya2; Marcel Hermans1; Vera Popovich1; 1TU Delft; 2Ghent University
    Wire + Arc Additive Manufacturing (AM) is a promising solution for large scale components, which enables fully-dense, near-net shape builds achievable throughout a vast array of alloy families. These material and geometrical flexibilities allow for multi-material AM and functional grading. Nevertheless, the dissolution of the tailored composition of a welding wire in a dissimilar weld deposit may lead to an undesirable material matrix with unexpected effects on the overall product’s performance. In this work, the interface region between a multi-bead deposit of high-strength S460 structural steel and an austenitic stainless steel 316L is studied. Extensive EBSD, EDS and XRD characterization are used to study the interface behavior, which clearly distinguishes itself from the neighboring material of nominal composition through the formation of a hard martensitic matrix alongside retained austenite. This work establishes a base for further studies of the mechanical properties of these graded components.

5:20 PM  
Large Scale Metal Additive Manufacturing for Infrastructure Repair: Zackery Mcclelland1; Kyle Dunsford1; 1US Army ERDC
    Aging infrastructure is a growing issue for our waterways navigation systems. Complex castings and long lead times can lead to reductions in trade navigation and adversely affect the economy. Each structure also requires custom cast components making large scale metal additive technologies a prime candidate for infrastructure repair. To this end, this effort studies the use of wire fed directed energy deposition (DED) to fabricate large metal components critical to infrastructure repair. The structure-property-performance of the deposited mild steel (ER70S) was studied to better understand the efficacy of using the material for the replacement of a 5 ft sector gear used in a lock structure. Microstructural (optical and scanning electron microscopy) and mechanical characterization (static tension and fully reversed fatigue R=-1) were run on both the deposited material and that of a cast 5 ft sector gear for comparison.

5:40 PM  
Operando Neutron Diffraction Characterization of Wire-Arc Deposited Steels: Alex Plotkowski1; Kyle Saleeby1; Chris Fancher1; James Haley1; Ke An1; Guru Madireddy1; Yousub Lee1; Tom Feldhausen1; Dunji Yu1; Clay Leach1; 1Oak Ridge National Laboratory
    A wire-arc directed energy deposition system was designed and constructed to enable operando characterization by neutron diffraction at ORNL’s Spallation Neutron Source. The system, called OpeN-AM, was used to fabricate components made of both mild and low-temperature transformation steels. Time-resolved neutron diffraction measurements were used to characterize phase changes during processing. At specific points during processing, neutron diffraction maps were also collected across the samples to characterize the lattice strain distributions. These measurements revealed the relationships between process dynamics and residual stress development, particular in relationship to the volume expansion during the austenite to martensite transformation in the LTT steel. These observations were also correlated with infrared data and computational modeling results. Results indicate the ability to control residual stress patterns through manipulations of the interaction between AM process dynamics and key material phase transformations, creating an opportunity for controlled residual stress states in manufactured components.