scholarly journals Hot Deformation Behavior of PM Ni with Harmonic Microstructure

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 90
Author(s):  
Cinzia Menapace ◽  
Bhupendra Sharma ◽  
Kei Ameyama
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Hot Compression ◽  
Metallographic Analysis ◽  
Diffusion Creep ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Temperature Spectrum ◽  
Wide Range

The hot deformation behavior of a harmonic-structured pure nickel has been studied and compared with the hot deformability of a homogeneously structured nickel. Both materials were produced via the powder metallurgy route through the Spark Plasma Sintering (SPS) of mechanical milled and un-milled powders. Hot deformation was evaluated through compression tests at three different temperatures (400 °C, 800 °C, and 1300 °C), covering a wide range in the homologous temperature spectrum for Ni (from 0.39 to 0.91), and at three different strain rates (0.001, 0.01, and 0.1 s−1). The evaluation of the stress–strain curves showed a higher hot compression resistance for the harmonic-structured nickel, together with higher strain hardening and strain rate sensitivity, thanks to the peculiar microstructural features of this material. Through the metallographic analysis of the specimens after hot compression, different mechanisms were identified as responsible for the deformation behavior in relation to the temperature of testing. While at 400 °C dynamic recrystallization has slightly started, at 800 °C it is widely diffused, and at 1300 °C it is replaced by grain growth and diffusion creep phenomena.

scholarly journals Characterization of Hot Deformation Behavior in a 13% Chromium Steel

2018 ◽  
Vol 941 ◽  
pp. 458-467
Author(s):  
Nima Safara Nosar ◽  
Fredrik Sandberg ◽  
Göran Engberg
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
Peak Stress ◽  
Chromium Steel ◽  
Hot Compression ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Hollomon Parameter

The behavior of a 13% chromium steel subjected to hot deformation has been studied by performing hot compression tests in the temperature range of 850 to 12000C and at strain rates from 0.01 to 10 s-1. The uniaxial hot compression tests were performed on a Gleeble thermo-mechanical simulator. The best function that fits the peak stress for the material and its relation to the Zener-Hollomon parameter (Z) is derived. The average activation energy of this alloy in the entire test domain was found to be about 557 [kJmol-1] and the dynamic recrystallization (DRX) kinetics was studied to find the fraction DRX during deformation.

Prediction of FV520B Steel Flow Stresses at High Temperature and Strain Rates

2015 ◽  
Vol 34 (6) ◽  
Author(s):  
Xiaolan Han ◽  
Shengdun Zhao ◽  
Chenyang Zhang ◽  
Shuqin Fan ◽  
Fan Xu
Keyword(s):  
High Temperature ◽  
Constitutive Equations ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Strain Rates ◽  
Isothermal Compression ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Wide Range ◽  
Steel Flow

AbstractIn order to develop reliable constitutive equations for the simulation, the hot deformation behavior of FV520B steel was investigated through isothermal compression tests in a wide range of temperatures from 900 °C to 1100 °C at an interval of 50 °C and strain rate from 0.01 to 10 s

Hot Deformation Behavior and Stability Criteria of WE54 Magnesium Alloy

2016 ◽  
Vol 879 ◽  
pp. 1618-1623 ◽  
Author(s):  
Ignacio Rieiro ◽  
Manuel Carsí ◽  
Oscar A. Ruano
Keyword(s):  
Magnesium Alloy ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Stability Criteria ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Logarithmic Curve ◽  
Efficiency Parameter

A precise description of the hot deformation behavior as well as determination of the stability conditions as influenced by temperature and strain rate is fundamental for the simulation of metal forming processes. In this work, a revision of various stability criteria of magnesium alloy WE54 is conducted. The study corresponds to own work and that of Lentz et al. and is based on compression tests at high temperature and high strain rates. Stability and processing maps were obtained using a variety of stability criteria, some based on the efficiency parameter η and others on the strain rate sensitivity parameter, m. This parameter is usually determined by fitting the curves strain rate, ε, versus stress, σ, by means of a potential equation named “power law” or by a polynomial of second or third degree, and calculating the slope of the logarithmic curve at each point using successive derivatives. This procedure is compared with one developed by us where all experimental points are fitted to a single hyperbolic sine equation of Garofalo type and then m and η are calculated for each ε and T using this equation. The maps obtained by one or the other method differ considerably. The predictions of these maps were contrasted with microstructural observations and conclusions on the deformation behavior of the alloy are reached.

Hot Deformation Behavior during the Hot Compression of AZ31 Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 545-548 ◽  
Author(s):  
Shu Li Sun ◽  
Min Gang Zhang ◽  
Wen Wu He ◽  
Jun Qi Zhou ◽  
Gang Sun
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
Flow Instability ◽  
Strain Curve ◽  
Az31 Alloy ◽  
Hot Compression ◽  
Instability Criterion ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Hollomon Parameter

The hot deformation behavior of as-cast AZ31 magnesium alloys have been investigated at 200~400°C and strain rates 0.001~1s-1 by means of hot compression tests on a Gleeble-1500D thermal-mechanical simulator. We have analyzed the flow stress-strain curve and presented the constitutive equation by calculating stress exponent, activation energy and Zemer-Hollomon parameter. Then, the processing map of AZ31 alloys has been developed based on the dynamic material model theories and Prasad instability criterion. The flow instability domain is observed at lower temperature and the larger power dissipation rate is emerging at 300~400°C. We have analyzed the corresponding deformation microstructures and it is characteristic of dynamic recrystallization. These results have shown that AZ31 alloy has good workability at 300~400°C and lower strain rate.

Hot Deformation Behaviour and Microstructural Evaluation of Zr-1Nb Alloy

2017 ◽  
Vol 890 ◽  
pp. 319-322 ◽  
Author(s):  
Kuldeep Kumar Saxena ◽  
Vivek Pancholi ◽  
Gajanan Prabhakar Chaudhari ◽  
Dinesh Srivastava ◽  
Gautam Kumar Dey ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
High Efficiency ◽  
Deformation Behaviour ◽  
Zirconium Alloys ◽  
Hot Compression ◽  
Compression Tests ◽  
Wide Range ◽  
Structural Applications

In nuclear water reactors, zirconium alloys are extensively used as fuel cladding material and in other structural applications. Uniaxial hot compression tests were performed to understand the deformation behavior of Zr-1Nb alloy. Therefore, hot compression tests were performed in the temperature range of 700-1050°C, which envelopes α-phase, (α+β) phase, and β-phase. True stress-strain curves, processing maps, microstructural observation and kinetic analysis were used to discuss the deformation behavior of Zr-1Nb alloy. Deformation at a strain rate of 10-2 s-1 reveals softening at lower temperatures and steady state behavior at higher temperatures. Processing map also reveals domain of high efficiency at 10-2 s-1 strain rate for a wide range of deformation temperatures. The flow softening and high power dissipation efficiency predicts dynamic recrystallization or dynamic recovery during the hot deformation of studied alloy.

Hot Deformation Behavior of a 3rd Generation Advanced High Strength Steel with a Medium-Mn Content

2015 ◽  
Vol 651-653 ◽  
pp. 120-125 ◽  
Author(s):  
Katharina Steineder ◽  
Martina Dikovits ◽  
Coline Beal ◽  
Christof Sommitsch ◽  
Daniel Krizan ◽  
...  
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
High Strength Steels ◽  
Rate Sensitivity ◽  
High Strength ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Present Contribution ◽  
Mn Content

Medium-Mn steels are one of the promising candidates to achieve the desired mechanical properties in the 3rd generation of cold rolled advanced high strength steels (AHSS) for automotive applications. Their duplex microstructure consists of a ferritic matrix with a substantial amount of metastable retained austenite, which transforms to strain-induced martensite upon forming. This strengthening mechanism, well known as the TRansformation Induced Plasticity (TRIP) effect, provides the steel an excellent combination of high strength and elongation with a product of RmxA80 up to 30.000 MPa%. As hot rolling is one of the crucial steps during their production, the hot deformation behavior of Medium-Mn steels has to be thoroughly evaluated during their development stage.Therefore, the present contribution studied the hot deformation response of a 0.1 %C 5.5 %Mn steel by means of hot compression tests using a Gleeble® 3800 device. The influence of different deformation temperatures (900-1100 °C) and strain rates (0.1-10 s-1) on the stress-strain behavior was investigated. The flow curves were analyzed and corrected by the effects of adiabatic heating.Furthermore, the strain rate sensitivity m of the material was determined by evaluating stress values at different strain rates for given temperatures and strains. The m-values can be used to predict the deformation behavior of the material within the investigated range of parameters.Lastly, the hot working behavior of an alternative steel concept for a 3rd Generation AHSS with significantly lower Mn-content was comparatively investigated.

Influence of Thermomechanical Parameters on the Hot Deformation Behavior of AA1070

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
H. R. Rezaei Ashtiani ◽  
H. Bisadi ◽  
M. H. Parsa
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Constitutive Equations ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Pure Aluminum ◽  
Engineering Practice ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Wide Range

The experimental stress–strain data from isothermal hot compression tests, in a wide range of temperatures (350–500 °C) and strain rates (0.005–0.5 s−1), were employed to develop constitutive equations in a commercially pure aluminum (AA1070). The effects of temperature and strain rate on the hot deformation behavior were represented by Zener–Hollomon parameter including Arrhenius term. The results show that the hardening rate and flow stress are evidently affected by both deformation temperature and strain rate. The power law, exponential, and hyperbolic sinusoidal types of Zener–Hollomon equations were used to determine the hot deformation behavior of AA1070. The results suggested that the highest correlation coefficient was achieved for the hyperbolic sine law for the studied material. So the proposed deformation constitutive equations can give an accurate and precise estimate of the flow stress for AA1070, which means it can be used for numerical simulation of hot forming processes and for choosing proper forming parameters in engineering practice accurately.

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