scholarly journals Constitutive Equation of GH4169 Superalloy and Microstructure Evolution Simulation of Double-Open Multidirectional Forging

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1146 ◽  
Author(s):  
Jin ◽  
Xue ◽  
Yang ◽  
Zhang ◽  
Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Constitutive Equation ◽  
Microstructure Evolution ◽  
Volume Fraction ◽  
Simulation Software ◽  
Maximum Temperature ◽  
Thermal Compression ◽  
Multidirectional Forging ◽  
Gh4169 Superalloy ◽  
Recrystallized Grain Size

This paper presented a double-open multidirectional forging with relatively few deformation passes and a uniform deformation. The constitutive equation and dynamic recrystallization model of the GH4169 superalloy were identified based on a thermal compression test and imported into Deform simulation software. The microstructure evolution law of GH4169 superalloy undergoing double-open multidirectional forging was simulated. The evolution of the recrystallization volume fraction and recrystallized grain size of the GH4169 superalloy during double-open multidirectional forging was obtained. Both higher temperatures and more passes were found to produce more complete recrystallization and smaller recrystallization grain size. At the maximum temperature studied, 1000 °C, with nine passes, the recrystallization volume fraction exceeded 95%, and the recrystallized grain size reached 3–5.5 µm.

scholarly journals Constitutive Model and Microstructure Evolution Finite Element Simulation of Multidirectional Forging for GH4169 Superalloy

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1695
Author(s):  
Yongbo Jin ◽  
Chenyang Xi ◽  
Peng Xue ◽  
Chunxiang Zhang ◽  
Sirui Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Parameter Selection ◽  
Compression Rate ◽  
Multidirectional Forging ◽  
Fine Grain ◽  
Suitable Parameter ◽  
Element Simulation ◽  
Gh4169 Superalloy ◽  
Recrystallized Grain Size

This study investigates three processes of multidirectional forging (MDF), namely, closed MDF (CMDF), single-open MDF, and double-open MDF, by using a constitutive equation and a dynamic recrystallization model of hot deformation of the GH4169 superalloy. The microstructure evolution of the three processes is simulated and compared. Among the three processes, the double-open MDF obtains the highest recrystallization degree, followed by the CMDF and the single-open MDF under the same reduction. The recrystallization degree of CMDF reaches 99.5% at 1000 °C and 9 passes, and the average recrystallized grain size is small, which is approximately 8.1 μm. The double-open MDF can obtain a fine grain size of forgings at 9 passes and 1000 °C, and it is easy to obtain forgings with the single-open MDF with uniform performance. The temperature is 850 °C–1000 °C, the compression rate is 0.15–0.2, and the pass is 5–9, which are the suitable parameter selection ranges for the CMDF. The temperature is 950 °C–1000 °C, the compression rate is 0.1–0.2, and the pass is 7–9, which are the suitable parameter selection ranges for single-open MDF. The temperature is 850 °C–1000 °C, the compression rate is 0.1–0.2, and the pass is 6–9, which are the suitable parameter selection ranges for the double-open MDF.

Finite Element Analysis on Microstructure Evolution of Hot Ring Rolling Process

2008 ◽  
Vol 575-578 ◽  
pp. 1455-1460 ◽  
Author(s):  
Zhi Chao Sun ◽  
He Yang ◽  
Xin Zhe Ou
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Volume Fraction ◽  
Small Deformation ◽  
Local Area ◽  
Rolling Process ◽  
Ring Rolling ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Average Grain Size

Hot ring rolling (HRR) is a 3D unsteady-state and coupled thermo-mechanical process, the metal undergoes complicated unequal deformation and microstructure evolution. In this paper a 3D rigid-plastic and coupled thermo-mechanical FEM model for hot ring rolling was developed based on DEFORM3D platform, taking dynamic recrystallization (DRX) volume fraction, DRX grain size, recystallization volume fraction and average grain size as objects, the mechanism of material microstructure evolution and distributions in HRR process are thoroughly studied. The results show that: with the HRR progressing, the DRX volume fraction, volume fraction, DRX grain size and average grain size have the similar distributing characteristic, and the distribution zones expand from a small local area into the whole ring strip, then diffuse to the mid-layer of ring with small deformation, their distributions become more uniform. Meanwhile with increase of deformation, the values of the DRX volume fraction and recrystallization volume fraction augment, i.e. the degree of recystallization increases. The DRX grain size also augments due to local high temperature, while the average grain size decreases. In general during HRR process the distributions of DRX volume fraction, recrystallization volume fraction, DRX grain size, and average grain size are ununiform due to unequal deforming in HRR process.

FE Analysis of Microstructure Evolution during Ring Rolling Process of a Large-Scale Ti-6Al-4V Alloy Ring

2010 ◽  
Vol 638-642 ◽  
pp. 223-228 ◽  
Author(s):  
Jong Taek Yeom ◽  
Jeoung Han Kim ◽  
Jae Keun Hong ◽  
Nho Kwang Park ◽  
Chong Soo Lee
Keyword(s):  
Grain Size ◽  
Prediction Model ◽  
Microstructure Evolution ◽  
Large Scale ◽  
Volume Fraction ◽  
Rolling Process ◽  
Ring Rolling ◽  
Forming Process ◽  
Microstructure Prediction ◽  
Ring Rolling Process

Microstructure evolution during ring rolling process of a large-scale Ti-6Al-4V ring was investigated with the combined approaches of three dimensional finite element method (FEM) simulation and microstructure prediction model. A microstructure prediction model was established by considering the volume fractions and grain size of  and  phases varying with process variables, and grain growth. In order to perform FE simulation for ring rolling process of Ti-6Al-4V alloy, a constitutive equation was generated by utilizing the flow stress data obtained from hot compression tests at different temperature and strain rate conditions. The volume fraction and grain size of  and  phases during ring rolling were calculated by de-coupled approach between FEM analysis and microstructure prediction model. The prediction results were compared with the experimental ones. Our proposed microstructure simulation module was useful for designing hot forming process of Ti-6Al-4V alloy

scholarly journals Study on Microstructure Evolution and Mechanical Properties of Ti2AlNb-Based Alloy under Canning Compression and Annealing

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 980 ◽  
Author(s):  
Wang ◽  
Xu ◽  
Sun ◽  
Zong ◽  
Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Microstructure Evolution ◽  
Texture Evolution ◽  
Annealing Treatment ◽  
Deformation Degree ◽  
Height Reduction ◽  
Schmid Factor ◽  
B2 Phase ◽  
Recrystallized Grain Size

The influence of height reduction on the microstructure evolution and mechanical properties of the Ti2AlNb-based alloy was investigated during canning compression and subsequent annealing. After the annealing treatment, the spheroidized B2 phase grains occurred because of partial recrystallization. Meanwhile, the texture evolution of the B2 phase and O phase were analyzed under the deformation degree, ranging from 25% to 75%. The results show that the mechanical properties of the post-annealed alloys were co-affected by the grain size and Schmid factor of the B2 phase. When the height reduction was less than 25%, the compression strength was mainly affected by the grain size. When the height reduction was higher than 50%, it was mainly dominated by the Schmid factor. When the deformation degree reached 75%, the recrystallized grain size decreased to 0.9 μm. Meanwhile, the Schmid factor of a {110}<001> slip system in B2 phase reduced to 0.34. Therefore, the yield strength of the Ti2AlNb alloy at room temperature increased from 892 MPa in the as-rolled condition to 935 MPa after the canning compression and annealing.

FE Analysis of Dynamical Recrystallization during the Seamless Tube Extrusion of Semicontinuous Casting Magnesium Alloy and Experimental Verification

2018 ◽  
Vol 37 (9-10) ◽  
pp. 961-971
Author(s):  
Tao Lin ◽  
Yun-teng Liu ◽  
Ji-xue Zhou ◽  
Yuan-sheng Yang ◽  
Zhu Yang
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Volume Fraction ◽  
Seamless Tube ◽  
Compression Tests ◽  
Tube Extrusion ◽  
Dynamical Recrystallization ◽  
Ram Speed ◽  
Recrystallized Grain Size ◽  
Two Parameters

AbstractIn this paper, empirical dynamic recrystallization (DRX) models for the semicontinuous AZ31 magnesium alloy were established based on the stress–strain curves and microstructure observations generated from hot compression tests. The DRX evolution during the seamless tube extrusion of the alloy was studied by numerical and experimental methods. The extruding temperature and the ram speed were two important parameters during the extrusion. With the increase of the two parameters, the volume fraction of DRX and the recrystallized grain size were observably increased. The predicted DRX fraction and grain size were in an excellent agreement with the experimental results.

Microstructure Evolution in a 304-Type Austenitic Stainless Steel during Multidirectional Forging at Ambient Temperature

2014 ◽  
Vol 783-786 ◽  
pp. 831-836 ◽  
Author(s):  
Alla Kipelova ◽  
Marina Odnobokova ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Volume Fraction ◽  
True Strain ◽  
Nanocrystalline Structure ◽  
Multidirectional Forging ◽  
Average Size ◽  
Structural Mechanisms

The formation of nanocrystalline structure in a 304-type austenitic stainless steel during multidirectional forging (MDF) at room temperature was investigated. Initial coarse austenite grains with an average size of 50 μm were refined to about 80 nm by martensitic transformation during MDF to a total true strain of 2 and remained unchanged upon further deformation up to a strain of 4. The volume fraction of martensite achieved ~0.9 after forging to a strain of 1.6. The MDF at room temperature was accompanied by a significant hardening of the 304-type steel. The microhardness and the flow stress increased during forging and approached their saturations on the levels of about 5 GPa and 1.7 GPa, respectively, after total true strain of 2. The structural mechanisms responsible for microstructure evolution during severe deformation are discussed.

Effect of Deformation Parameters on Microstructure Evolution of Hot Deformed Superalloy GH4169

2015 ◽  
Vol 744-746 ◽  
pp. 1382-1385
Author(s):  
Tong He ◽  
Jing Hong Tuo ◽  
Zhi Hua Li ◽  
Qing An Tai
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Microstructure Evolution ◽  
Temperature Increase ◽  
Compression Tests ◽  
Rate Decrease ◽  
Microstructural Parameters ◽  
Nickel Based Superalloy ◽  
Deformation Parameters ◽  
Recrystallized Grain Size

The evolution of the microstructure of a typical nickel-based superalloy GH4169 is investigated by the hot compression tests. The microstructural parameters such as fraction of recrystallization and grain size were analysed quantitatively. The results show that the effects of deforming temperature and strain rate on the dynamic recrystallized grain size are significant. With the deformed temperature increase and the strain rate decrease, the dynamic recrystallized grain size increases.

A Mesoscopic Modelling Framework of Microstructure Evolution and its Application on Thermo-Mechanical Processes

2021 ◽  
Vol 1035 ◽  
pp. 792-800
Author(s):  
Na Min Xiao ◽  
Ai Xue Sha ◽  
Xing Wu Li
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Solid Phase ◽  
Field Method ◽  
Phase Field Method ◽  
Thermomechanical Process ◽  
Modelling Framework ◽  
Mesoscopic Modelling ◽  
The Matrix ◽  
Recrystallized Grain Size

In present study a quantitative modelling framework based on phase-field method is developed to simulate the microstructure evolution during thermomechanical process, e. g. grain growth, recrystallization, solid phase transformations and their interactions. Two application cases of microstructure evolution are introduced. The first one is the dynamic recrystallization behavior during the hot deformation of stainless steel. The effect of thermo-mechanical parameters including strain, strain rate, and temperature on DRX have been investigated quantitatively. Moreover, the present simulation provided an explanation of the dependence of final recrystallized grain size on initial grain size when it is decreased to a critically small value. This modelling framework is also used to simulate the interaction between the dissolution of precipitates and grain coarsening of matrix in the nickel alloys. The simulation results show that the decreasing dissolution temperature of precipitate slow down the matrix coarsening kinetics obviously. This provides an quantitative tool to predict and control the local microstructure of nickel alloy disk. In summary, the mesoscopic modelling can be used to investigate more kinetic details of microstructure evolution and engineering optimization for thermo-mechanical process.

scholarly journals Prediction of Microstructure Evolution in Hot Backward Extrusion of Ti-6Al-4V Alloy

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Jong-Taek Yeom ◽  
Jeoung Han Kim ◽  
Jae-Keun Hong ◽  
Nho-Kwang Park ◽  
Chong Soo Lee
Keyword(s):  
Grain Size ◽  
Prediction Model ◽  
Microstructure Evolution ◽  
Volume Fraction ◽  
Fem Analysis ◽  
Close Relation ◽  
Extrusion Process ◽  
Forming Process ◽  
Backward Extrusion ◽  
Microstructure Prediction

Microstructure evolution of Ti-6Al-4V alloy during hot backward extrusion process was simulated with the combined approaches of finite element method (FEM) and microstructure prediction model. From experimental analysis, it can be found that the change of microstructure during hot forming process of titanium alloy has a close relation to α/β phase transformation and grain growth behaviour. A microstructure prediction model was established by considering the change of volume fractions and grain size of both phases varying with process variables and then implemented into the user-defined subroutine of FEM analysis. In order to demonstrate the reliability of the model, the volume fraction and grain size of primary α phase during the hot backward extrusion process of Ti-6Al-4V alloy were simulated. The simulation results were compared with the experimental ones.

Sign in / Sign up

Export Citation Format

Share Document