Strain-Induced Martensite Formation of AISI 304L Steel Sheet: Experiments and Modeling

2016 ◽  
Vol 869 ◽  
pp. 490-496 ◽  
Author(s):  
D.C.T. Costa ◽  
M.C. Cardoso ◽  
Gláucio S. da Fonseca ◽  
Luciano Pessanha Moreira ◽  
M. Martiny ◽  
...  
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Phenomenological Model ◽  
Steel Sheet ◽  
Strain Curve ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Aisi 304L ◽  
Strain Induced Martensite ◽  
304L Steel

Metastable austenitic stainless steels are prone to strain-induced martensite transformation (SIMT) during deformation at room temperature, as in the case of sheet metal forming processes. The SIMT is influenced by the chemical composition, grain size, temperature, deformation mode or stress state and strain-rate. In this work, interrupted and continuous uniaxial tensile tests were performed in AISI 304L sheet to evaluate the SIMT as a function of strain and strain-rate effects. The SIMT was evaluated by feritscope and temperature in-situ measurements and both XRD and optical microscopy techniques. The SIMT kinetics was also investigated by means of thermo-mechanical finite element simulations using a phenomenological model. In the small strain range, the yield stress increases with the strain-rate whereas in the large strain domain a cross-effect in the stress-strain curve is observed given that the SIMT is inhibited due to the specimen heat generation. A very good correlation between XRD and feritscope measurements was found from the interrupted uniaxial tensile testing. The finite element numerical simulations allowed to identify the parameters of a phenomenological model which describes the SIMT kinetics of AISI 304L steel sheet as a function of plastic-strain, strain-rate and temperature effects.

Effects of Strain-Rate and Deformation Mode on Strain-Induced Martensite Transformation of AISI 304L Steel Sheet

2016 ◽  
Vol 835 ◽  
pp. 216-221
Author(s):  
Alexandre de Melo Pereira ◽  
Marcelo Costa Cardoso ◽  
Luciano Pessanha Moreira
Keyword(s):  
Strain Rate ◽  
Plane Strain ◽  
Strain Curve ◽  
Deformation Mode ◽  
Image Correlation ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Aisi 304L ◽  
Plane Strain Tension ◽  
Uniaxial Tensile Testing

Metastable austenitic stainless steels are prone to strain-induced martensitic transformation (SIMT) during deformation at room temperature, as in the case of sheet metal forming processes. SIMT is influenced by chemical composition, grain size, temperature, deformation mode or stress state and strain-rate effects. In this work, uniaxial and plane-strain tension tests were performed in AISI 304L sheet to evaluate the SIMT as a function of strain-rate. Feritscope and temperature in-situ measurements were performed during the uniaxial tensile testing. Digital image correlation (DIC) technique was employed to determine the in-plane surface strains of the plane-strain tension specimen. From the uniaxial tensile and plane-strain tension results, the yield stress increased with the strain-rate in the small strain range whereas a cross-effect in the stress-strain curve is exhibited in the large strain domain. This effect is attributed to the specimen heat generation, which inhibits the SIMT phenomenon. Conversely, plane-strain deformation mode displayed a higher SIMT rate and an improved work-hardening behavior in comparison to the uniaxial tensile straining.

Elasto-plastic and creep behaviour of axially loaded, shouldered tubes

1980 ◽  
Vol 15 (1) ◽  
pp. 21-29 ◽  
Author(s):  
R J Dawson ◽  
H Fessler ◽  
T H Hyde ◽  
J J Webster
Keyword(s):  
Finite Element ◽  
Creep Behaviour ◽  
Equivalent Stress ◽  
Strain Curve ◽  
Equivalent Strain ◽  
Uniaxial Tensile ◽  
Plastic Strain Increment ◽  
Axially Loaded ◽  
Initial Strains ◽  
Creep Strains

This paper compares the finite element predictions of elasto-plastic and creep behaviour with experimental data for axially loaded, shouldered tube models. Four shouldered tube models were made of a lead alloy and tested at 61°C, using strain gauges to measure the elasto-plastic and creep strains in the plain tube and fillet regions of the models. Instantaneous stress-strain and creep data were obtained from strain-gauged, uniaxial tensile specimens. The finite element solutions are based on the incremental Prandtl-Reuss equations. The elasto-plastic iterative solutions use a ‘negative gradient’ from the calculated point to the equivalent stress-equivalent strain curve to get the next estimate of the plastic strain increment. A time incremental method is used to obtain the creep solutions. Tests with the mean tube stress below, at and above the yield stress showed very good agreement between prediction and measurement of initial strains in the fillets. Differences between predictions and measurements of creep strains are attributable to cast-to-cast variations.

scholarly journals Influence of Deformation Controlled Strain Rate on Tensile and Compression Behaviour of Magnesium and Steel Wire

2017 ◽  
Vol 892 ◽  
pp. 89-96 ◽  
Author(s):  
Thorsten Henseler ◽  
Madlen Ullmann ◽  
Grzegorz Korpala ◽  
Klaudia Klimaszewska ◽  
Rudolf Kawalla ◽  
...  
Keyword(s):  
Strain Rate ◽  
Elevated Temperatures ◽  
Steel Wire ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
Strain Curve ◽  
Compression Testing ◽  
Uniaxial Tensile ◽  
Flow Curves ◽  
The Difference

This article demonstrates the difference in the flow curves of an AZ31 magnesium alloy and S235JR structural steel wire caused by non-linear strain rates during uniaxial tensile and compression testing at elevated temperatures. Throughout tensile deformation, the traverse velocity of the testing machine has to be adapted according to the current elongation of the specimen, thus accelerating, to ensure a constant strain rate during the admission of the stress-strain curve. The equivalent is necessary during compression testing, where the traverse velocity of the testing machine needs to decelerate ensuring a constant strain rate. Nevertheless, tensile and compression tests are performed with constant traverse velocity, which lead to divergent flow curves in comparison to deformation controlled traverse velocities. The results of the research show the difference in flow behaviour of magnesium and steel wire, when the temperature and strain rate are varied in conjunction with constant and deformation controlled traverse velocities.

Deformation and Fracture Behavior of 7039 Al Reinforced with B4C Particles at Elevated Temperature

2007 ◽  
Vol 351 ◽  
pp. 65-69 ◽  
Author(s):  
Cun Zhu Nie ◽  
Jia Jun Gu ◽  
Jun Liang Liu ◽  
Di Zhang
Keyword(s):  
Elevated Temperature ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Aluminum Matrix ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Initial Strain ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Deformation And Fracture

The elevated temperature deformation and fracture behavior of an 10vol%B4CP/7039 aluminum matrix composite plate was investigated by uniaxial tensile tests at temperatures ranging from573 to 773 K and at initial strain rates from 1x10-1 to 1x10-4s-1.The strain rate sensitivity exponent was found to be approximately 0.1-0.15 which was below that of a superplastic material. A maximum elongation of 116% was obtained at an initial strain rate of 10-1 s-1 and at a temperature of 773 K.

Constitutive Analysis and Microstructure Evolution of the High-Temperature Deformation Behavior of an Advanced Intermetallic Multi-Phase γ-TiAl-Based Alloy

2014 ◽  
Vol 922 ◽  
pp. 807-812 ◽  
Author(s):  
Robert Werner ◽  
Emanuel Schwaighofer ◽  
Martin Schloffer ◽  
Helmut Clemens ◽  
Janny Lindemann ◽  
...  
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Thermomechanical Processing ◽  
True Strain ◽  
Strain Curve ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Nominal Composition ◽  
Compression Tests

In the present study the high-temperature deformation behavior of a caste and subsequently HIPed β-solidifying γ-TiAl-based alloy with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in at. %), termed TNM alloy, is investigated. At room temperature this alloy consists of ordered γ-TiAl, α2-Ti3Al and βo-TiAl phases. By increasing the temperature, α2and βodisorder to α and β, respectively. In order to get a better understanding of dynamic recovery and recrystallization processes during thermomechanical processing, isothermal compression tests on TNM specimens are carried out on a Gleeble®3500 simulator. These tests are conducted at temperatures ranging from 1100 °C to 1250 °C (in the α/α2+β/βo+γ phase field region) applying strain rates in the range of 0.005 s-1to 0.5 s-1up to a true strain of 0.9. The evolution of microstructure along with the dynamically recrystallized grain size during hot deformation is examined by scanning electron microscopy (SEM). The flow softening behavior after reaching the peak stress in the true stress-true strain curve is attributed to dynamic recrystallization. By using the Zener-Hollomon parameter as a temperature-compensated strain rate the dependence of flow stress on temperature and strain rate is shown to follow a hyperbolic-sine Arrhenius-type relationship.

The Effects of Temperature, Strain Rate, and Aging on the Poisson’s Ratio of SAC Lead Free Solders

2018 ◽  
Author(s):  
K. M. Rafidh Hassan ◽  
Mohammad S. Alam ◽  
Munshi Basit ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Lead Free ◽  
Uniaxial Tensile ◽  
Automatic Data ◽  
Effects Of Temperature ◽  
Lead Free Solders ◽  
Temperature Strain

In this study, we have conducted a combined numerical and experimental study on the Poisson’s ratio of SAC lead free solders. The Poisson’s ratio (PR) is one of the basic mechanical properties used in many material constitutive models. Although often not measured, it is important property in many finite element method (FEM) calculations. The value of the Poisson’s ratio of SAC lead free solders is relatively unexplored compared to other material properties, and for FEA simulations it is typically assumed to be v = 0.3. In the current work, we have shown the effects of the chosen value of the solder joint Poisson’s ratio on the finite element results for BGA components subjected to thermal cycling. In the finite element models, the reliability predictions were based on the Morrow-Darveaux energy-based fatigue model. Several sizes (5, 10, 15 mm) of PBGA components with SAC305 solder joints with 0.4 and 0.8 mm spacing were modeled. The packages were subjected to a time dependent cyclic temperature distribution from −40 to 125 °C. The package assemblies were assumed to be in a stress-free state at 25 °C (room temperature), with no residual stresses induced in the manufacturing process. The simulation results have demonstrated that for specified range of Poisson’s ratio values of 0.15 < v < 0.40, the solder Plastic Work varied over 20% and the Predicted Reliability Varied over 50%. To determine the actual Poisson’s ratio experimentally, uniaxial tensile stress-strain tests were carried out on SAC305 (96.5Sn3.0Ag0.5Cu) specimens using a micro tension/torsion testing machine with two strain rates (0.0001, and 0.00001 (sec−1)), four testing temperatures (T = 25, 50, 75, 100 °C), and several durations of prior aging at T = 125 °C. Deformations and strains in axial and transverse directions were measured using strain gages with automatic data acquisition from LabVIEW software. The recorded transverse strain vs. axial strain data were then fit with a linear regression analysis to determine the Poisson’s ratio values. A test matrix of experiments was developed to study the effects of temperature, strain rate, alloy composition, and solidification cooling profile on the value of solder Poisson’s ratio. The Poisson’s ratio was found to increase with increasing temperature, and decrease with increasing strain rate. Using a slower solidification cooling profile led to an increase in the solder Poisson’s ratio value. Finally, the microstructural coarsening that occurs during isothermal aging lead to an increase in the Poisson’s ratio.

scholarly journals A Simple and Efficient Method for Obtaining the Whole-Range Uniaxial Tensile Properties of Pipeline Steel

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 555
Author(s):  
Lingzhen Kong ◽  
Lingbo Su ◽  
Xiayi Zhou ◽  
Liqiong Chen ◽  
Jie Chen ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pipeline Steel ◽  
True Strain ◽  
Strain Curve ◽  
Element Model ◽  
True Stress ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Output Data

To obtain the whole-range true stress-true strain curves of API X65, a method is proposed based on the equal proportion principle and digital images. The tensile elongation was obtained by tracing the gauge points on the specimen surface, and the true strain and true stress of API X65 were calculated according to the formulae. The obtained true stress-true strain curves were validated by a 3-D finite element model. The true stress-true strain curve was set as the input data, while the engineering stress-engineering strain curve was set as the output data. The output data of the finite element model was the same as that of the experiment test. The findings imply that the proposed method could acquire reliable, whole-range true stress-true stain curves. These curves, which depict the material behavior of pipeline steel from initial elongation to fracture, could provide basic data for pipeline defect tolerance limit analysis and fracture assessment.

Numerical modeling of the effects hydration and number of hydrogen bonds on the mechanical properties of the tropocollagen molecule

2020 ◽  
Vol 234 (3) ◽  
pp. 299-306 ◽  
Author(s):  
Marouane El Mouss ◽  
Amna Rekik ◽  
Said Zellagui ◽  
Tarek Merzouki ◽  
Ridha Hambli
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Hydrogen Bonds ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Collagen Molecule ◽  
Uniaxial Tensile ◽  
Type I ◽  
Two Parameters

Bone aging involves structural and molecular modifications, especially at the level of type I tropocollagen. This macromolecule shows two main age-related alterations, which are the decrease of both molecular diameter (due to the loss of hydration) and number of hydrogen bonds. In this work, it is proposed to investigate the influence of these two parameters (molecular diameter and number of hydrogen bonds) on the mechanical behavior of tropocollagen using finite element method. To this end, a novel three-dimensional finite element model of collagen molecule accounting for hydrogen bonds was developed. Then, a numerical design of experiments for the diameter of tropocollagen and variations in the number of hydrogen bonds has been established. The mechanical properties (“load–strain” curve and apparent Young’s modulus) of the collagen molecule were obtained by employing the proposed model to uniaxial tensile tests. The parametric study demonstrates that the mechanical properties of tropocollagen are slightly affected by the rate of hydration but considerably affected by variation of the number of hydrogen bonds. Finally, a fitted analytical function was deduced from the above results showing effects of the two parameters (hydration rate and hydrogen bonds) on the apparent Young’s modulus of tropocollagen. This study could be useful to understand the influence of structural age modifications of tropocollagen on the macroscopic mechanical properties of bone.

High Temperature Deformation Behavior of 25Cr5MoA Nitriding Steel

2011 ◽  
Vol 399-401 ◽  
pp. 240-244
Author(s):  
Yue Zang ◽  
Shu Xia Li ◽  
Yi Kun Yang ◽  
Xue Ping Ren
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Temperature ◽  
True Strain ◽  
Strain Curve ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Deformation Degree

The high temperature deformation law of nitriding steel 25Cr5MoA over the strain rate range 0.001S-1~20S-1and temperature range 850°C to 1150°C was studied in the thermal simulation testing machine Gleeble-1500. Under a certain strain rate and a certain deformation degree, the flow stress decreased with the increase of deformation temperature. Work hardening of nitriding steel 25Cr5MoA was strong when the true strain was less than 0.2, otherwise the flow stress increased slowly, even dropped. High temperature deformation flow stress of nitriding steel 25Cr5MoA was influenced by the deformation temperature and strain rate. When the strain rate was 0.1S-1, true stress-true strain curve exhibited a dynamic recrystallization model, and with the increase of deformation temperature, peak flow stress shift left. When deformation degree was 0.69, the strain rate was 1S-1, and when deformation temperature was in the region of 850°C~1050°C, true stress-true strain curve exhibited a dynamic recovery model. And when the deformation temperature was in the region of 1100°C~1150°C, it showed a dynamic recrystallization model. Dynamic recrystallization diagrams of nitriding steel 25Cr5MoA were also established.

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