The delay loop phenomenon in high temperature elasticity modulus test by in-situ ultrasonic measurements

Xue, Huan; Liu, Dong; Ge, Rui; Pan, Lin; Peng, Wenjie

doi:10.1016/j.measurement.2020.107833

Cited by 7 publications

(4 citation statements)

References 28 publications

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“…This phenomenon occurs because the modulus of steel undergoes a two‐stage change as the temperature increases, with an initial slow decrease followed by a rapid decrease. [ 21 ] Interestingly, the load–temperature curves for various initial loads closely coincide once the temperature exceeds 600 °C. For comparison, specimens were subjected to continuous heating up to the target temperature, followed by rapid water cooling.…”

Section: Resultsmentioning

confidence: 92%

Investigation on Recrystallization Behavior of Cold‐Rolled Silicon Steel in Continuous Heating with Three‐Point Bending Testing

Liu,

Fang,

Liu

et al. 2024

steel research int.

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Understanding the recrystallization behavior of cold‐rolled silicon steel during continuous heating is essential for optimizing continuous annealing parameters and accurately controlling material performance. To address the limitations of isothermal annealing studies in interpreting actual continuous annealing processes, this study investigates the recrystallization kinetics of Fe–2.3 wt%Si steel using a continuous heating three‐point bending method. The method effectively determines the characteristic recrystallization temperatures. Interestingly, these recrystallization characteristic temperatures remain unaffected by the initial load but shift toward higher temperatures with increasing heating rates in the range of 5–15 °C min−1. The average activation energy of recrystallization is estimated to be 144.5 kJ mol−1, comparable to the value of 147.0 kJ mol−1 obtained from the isothermal process through microhardness measurement. The recrystallization kinetics, described by an extended version of the Ozawa–Flynn–Wall model, exhibits excellent agreement with experimental evaluations. By combining the present processing technologies with continuous heating recrystallization kinetics, different recrystallization temperatures and times can be determined, offering valuable insights for optimizing annealing processes.

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Section: Resultsmentioning

confidence: 92%

Investigation on Recrystallization Behavior of Cold‐Rolled Silicon Steel in Continuous Heating with Three‐Point Bending Testing

Liu,

Fang,

Liu

et al. 2024

steel research int.

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“…При высоких температурах упругие модули зависят от температуры, что подтверждается экспериментально [21][22][23][24][25][26]. Для нашего случая применяем их линейную зависимость:…”

Section: основы математической моделиunclassified

The influence exerted by active cooling on the permanent connection formed as a result of electric arc welding

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Abashkin

2022

PNRPU Mechanics Bulletin

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The problem of temperature stresses is solved in the work. The process of electric arc welding with guaranteed penetration of steel plates of various thicknesses is simulated. The possibility of reducing residual stresses formed as a result of welding by applying heat removal from the surface of the near-weld region of a steel plate is being investigated. The temperature distribution is determined by solving a non-linear heat equation, in which the specific heat and thermal conductivity depend on temperature. The heat source is modeled using the double ellipsoid method proposed by John A. Goldak. The horseshoe-shaped heat sink follows immediately after the anode spot and is set by the heat flux in such a way that the main temperature of the plate does not decrease below its initial temperature. This limitation reduces the level of the temperature gradient, thereby reducing the stresses in the metal plate. To illustrate the effect of active heat sink, the temperature distribution in the top layer at the moment of termination of welding is compared with and without active heat sink. The material is assumed to be elastoviscoplastic, the deformations are small and consist of reversible and irreversible ones. Reversible deformations are related to stresses by the Duhamel - Neumann law. Irreversible strains increase when the von Mises plastic flow condition is satisfied, in which there is a plastic strain rate component responsible for the plastic flow viscosity. The elastic moduli (Young's modulus, Poisson's ratio) and the yield strength are assumed to be temperature dependent. The solution of the mechanical part of the problem is found by the method of simple iterations. For plates with different thicknesses, diagrams of residual stresses are given, located in the center of the plate from the seam to the periphery. As a result of the work, according to the obtained distributions of residual stresses in the plate material, it is concluded that the use of an active horseshoe-shaped heat sink from the near-weld zone when welding thin steel plates reduces residual stresses, therefore it is recommended to use in the welding process. The use of an active heat sink on the reverse side of the plate leads to an increase in the stress level, therefore it is not recommended for use.

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“…The vibrational signal is registered in the time domain and converted to the frequency domain through Fourier transformation. Young’s modulus is calculated with Equations (1) and (2) [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ].

where: E —Young’s modulus [Pa]; m —mass of the bar [g]; b —width of the bar [mm]; L —length of the bar [mm]; t —thickness of the bar [mm]; f f —fundamental flexural resonant frequency of bar [Hz]; T —correction factor for the fundamental flexural mode that accounts for the finite thickness of bar, Poisson’s ratio; ν —Poisson’s ratio.…”

Section: Introductionmentioning

confidence: 99%

“…Ultrasonic flaw detectors with broadband transducers are used to determine elastic constants. Young’s modulus is calculated using Equation (3) [ 15 , 16 , 17 , 18 ].

where: E — Young’s modulus [Pa]; V L —ultrasonic wave speed [m/s]; ρ —density [kg/m 3 ] ν — Poisson’s ratio.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Analysis of Selected Methods for Determining Young’s Modulus in Polylactic Acid Samples Manufactured with the FDM Method

et al. 2021

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The objective of this study was to compare three methods for determining the Young’s modulus of polylactic acid (PLA) and acrylonitrile-butadiene-styrene (ABS) samples. The samples were manufactured viathe fused filament fabrication/fused deposition modeling (FFF/FDM) 3D printing technique. Samples for analysis were obtained at processing temperatures of 180 °C to 230 °C. Measurements were performed with the use of two nondestructive techniques: the impulse excitation technique (IET) and the ultrasonic (US) method. The results were compared with values obtained in static tensile tests (STT), which ranged from 2.06 ± 0.03 to 2.15 ± 0.05 GPa. Similar changes in Young’s modulus were observed in response to the processing temperatures of the compared methods. The values generated by the US method were closer to the results of the STT, but still diverged considerably, and the error exceeded 10% in all cases. Based on the present findings, it might be concluded that the results of destructive and nondestructive tests differ by approximately 1 GPa.

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The delay loop phenomenon in high temperature elasticity modulus test by in-situ ultrasonic measurements

Cited by 7 publications

References 28 publications

Investigation on Recrystallization Behavior of Cold‐Rolled Silicon Steel in Continuous Heating with Three‐Point Bending Testing

Investigation on Recrystallization Behavior of Cold‐Rolled Silicon Steel in Continuous Heating with Three‐Point Bending Testing

The influence exerted by active cooling on the permanent connection formed as a result of electric arc welding

A Comparative Analysis of Selected Methods for Determining Young’s Modulus in Polylactic Acid Samples Manufactured with the FDM Method

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