Correlation of Microstructure With HAZ Welding Cycles Simulated in Ti-15-3 Alloy Using Gleeble® 3800 and SYSWELD®
03 Aug 2015-Materials Performance and Characterization (ASTM International)-Vol. 4, Iss: 3, pp 381-398
TL;DR: In this article, a combination of computational and physical simulation tools is proposed to reduce the cycle to find an optimal choice in the fabrication process design space, where both continuous and pulsed welding conditions are used for the welding process.
Abstract: Metastable β-titanium alloys are finding increasingly wider applications in structural components in aerospace, energy, and chemical industries because of their formability and heat-treatment possibilites. Components from these alloys are usually welded by processes, such as gas tungsten arc welding (GTAW), electron beam welding (EBW), and laser beam welding (LBW). Post-weld heat treatment improves the strength of the weld because of the precipitation of α phase and TiCr2 particles. In β-titanium alloys, the location, distribution and morphology of α precipitates in β matrix plays an important role in the performance of the welded components. In this work, we simulate different welding processes using SYSWELD® software and obtain realistic thermal cycles after calibrating the fusion zone dimensions with known experimental data. These cycles are then used to program the heat-affected zone (HAZ) cycles in Gleeble® 3800 to study their effect on the microstructure of the β-titanium alloy. Both continuous and pulsed welding conditions are used for the welding process. Microstructure characterization was performed using scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD), and transmission electron microscopy (TEM). Precipitates of α phase below 0.2μm are seen to be uniform across the β grain but the number density is not uniform across different grains of β. We discuss the characterization results in light of existing models in the literature. The α precipitation and hardness variation are correlated with welding cycles. A combination of computational and physical simulation tools is proposed to reduce the cycle to find optimal choice in the fabrication process design space.
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01 Sep 2020
TL;DR: An integrated computational materials engineering (ICME)-based workflow was adopted for the study of microstructure and property evolution at the heat-affected zone (HAZ) of gas metal arc-welded DP980 steel as discussed by the authors.
Abstract: An integrated computational materials engineering (ICME)-based workflow was adopted for the study of microstructure and property evolution at the heat-affected zone (HAZ) of gas metal arc-welded DP980 steel. The macroscale simulation of the welding process was performed with finite element method (FEM) implemented in Simufact Welding® software and was experimentally validated. The time–temperature profile at HAZ obtained from FEM simulation was physically simulated using Gleeble 3800® thermo-mechanical simulator with a dilatometer attachment. The resulting phase transformations and microstructure were studied experimentally. The austenite-to-ferrite and austenite-to-bainite transformations during cooling at HAZ were simulated using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation implemented in JMatPro® software and with phase-field modeling implemented in Micress® software. The phase fractions and the phase transformation kinetics simulated by phase-field method agreed well with experiments. A single scaling factor introduced in JMatPro® software minimized the deviation between calculations and experiments. Asymptotic homogenization implemented in Homat® software was used to calculate the effective macroscale thermo-elastic properties from the phase-field simulated microstructure. FEM-based virtual uniaxial tensile test with Abaqus® software was used to calculate the effective macroscale flow curves from the phase-field simulated microstructure. The flow curve from virtual test simulation showed good agreement with the flow curve obtained with tensile test in Gleeble®. An ICME-based vertical integration workflow in two stages is proposed. With this ICME workflow, effective properties at the macroscale could be obtained by taking microstructure morphology and orientation into consideration.
4 citations
Cites methods from "Correlation of Microstructure With ..."
...[6] simulated welding in titanium alloy with finite element method and used physical simulation in Gleeble 3800® to simulate the heat-affected zone (HAZ) welding cycles....
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TL;DR: In this article , the additive manufacturing of eutectic high-entropy alloys (EHEAs) with seven components was simulated and the results showed that the sigma phase was formed in the primary dendritic phase.
3 citations
TL;DR: In this paper, an Integrated Computational Materials Engineering (ICME) methodology was proposed to identify optimum dilution levels for welded components used during high-temperature aging to obtain the best possible lifetime for the component.
Abstract: The microstructure stability of welded power plant steel components is typically assessed using the precipitate growth kinetics The long-term exposure of welded structures at high temperatures results in coarsening of precipitates which may lead to the failure of the components The dilution of base and filler material in the weldment could give rise to detrimental precipitates The present work proposes an Integrated Computational Materials Engineering (ICME) methodology to identify optimum dilution levels for welded components used during high-temperature aging to obtain best possible lifetime for the component For this study, the TC-PRISMA® module of ThermoCalc® software was used for precipitation calculations after appropriate benchmarking Weld dilution study was performed to predict dilution effect influence on Laves phase precipitates in a welded component of CB2 and P92 steels during aging for up to 100,000 h From the dilution study, it was found that the composition of the weld affects the size and coarsening of the Laves phase precipitate It was also observed that the size of Laves phase precipitates for all dilution ratios remains within the critical size limit for CB2 steel and it exceeds the critical size limit in P92 steel during aging Based on the study, an ICME workflow was proposed to determine the optimum dilution ratio for welded power plant steel components used in high-temperature applications for obtaining the best possible lifetime for the component and to reduce the associated cost of experimental trials
1 citations
09 Oct 2022
TL;DR: In this article , an overview of microstructure simulation and a set of two examples are presented to illustrate the role of a second thermal cycle on reducing distortions and on predicting phase evolution.
Abstract: Arc welding involves thermal cycles that lead to phase transformations as well as residual stresses. Alloys that are designed to have specific microstructures obtained through thermo-mechanical treatment are prone to losing their properties in the heat-affected zone as well as fusion zone. One can design a second thermal cycle in such a way as to reduce the residual stress to control distortion or lead to phase transformations that can compensate for the loss of properties. Such studies require multiscale modeling involving welding at system scale as well as microstructural models. While there are models available for phase transformations, detailed modeling of microstructure evolution is necessary in alloys such as dual phase steels. In this chapter, an overview of microstructure simulation and a set of two examples are presented to illustrate the role of a second thermal cycle on reducing distortions and on predicting phase evolution.
TL;DR: In this article , three different heat affected zones (HAZ) in hot rolled Nickel Free High Nitrogen Stainless Steels (NFHNSS) based on three different peak temperatures were physically simulated using Gleeble Simulator to investigate microstructural evolution and structure-property correlation.
Abstract: Three different Heat Affected Zones (HAZ) in hot rolled Nickel Free High Nitrogen Stainless Steels (NFHNSS) based on three different peak temperatures were physically simulated using Gleeble Simulator to investigate microstructural evolution and structure-property correlation. Optical microscopy revealed that the austenite grains are recrystallized in the simulated heat affected zone in the peak temperature range of 750 oC to 1050 oC. Extent of recrystallization of grains and nucleation of precipitates varied with peak temperatures. TEM characterization showed the presence of Cr2N precipitate having an average particle size in the range of 300 nm to 395 nm in the simulated HAZ were confirmed by Selected Area Electron Diffraction (SAED) analysis. Precipitation kinetics of Cr2N were simulated using Thermo-Calc were found to correlate well with experimental values. Mechanical properties of specimens taken from three different HAZ were evaluated for tensile strength and hardness. Variation in strength of the different specimens has been discussed using various strengthening models. Fractography analysis was also carried out to understand the effect of peak temperature on fracture behaviour. Transition in fracture patterns in NFHNSS from ductile to mixed mode was observed for different specimens.
References
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TL;DR: In this article, a double ellipsoidal geometry is proposed to model both shallow penetration arc welding processes and the deeper penetration laser and electron beam processes, which can be easily changed to handle non-axisymmetric cases such as strip electrodes or dissimilar metal joining.
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428 citations
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297 citations
01 Jan 1971
TL;DR: In this paper, the effect of ternary additions of Al, O, Sn, and Zr on the decomposition of metastable Ti-Mo and Ti-V Β-phase alloys has been studied.
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155 citations
TL;DR: The microstructure development in Ti-15V-3Cr-3Sn-3Al alloy by various thermomechanical processings is reviewed in this paper, where the competition of recovery/recrystallization of β matrix and α precipitation takes place.
131 citations