Recrystallization Behaviors of an Al-Zn-Mg-Cu Alloy during Multi-Pass Hot Compression

2010 ◽  
Vol 638-642 ◽  
pp. 327-332 ◽  
Author(s):  
Jian Shen ◽  
Ju Peng Li ◽  
Liang Ming Yan ◽  
Xiao Dong Yan
Keyword(s):  
Microstructure Evolution ◽  
Rolling Process ◽  
Hot Compression ◽  
Compression Tests ◽  
Slow Cooling ◽  
7050 Aluminum Alloy ◽  
Subgrain Growth ◽  
Nucleation Mechanisms ◽  
Different Temperatures ◽  
Thermomechanical Processes

Dynamic recovery (DRV) and dynamic recrystallization (DRX) play important roles during thermomechanical processes of light metals and alloys because they have obvious influence on microstructure evolution and finally on the mechanical properties of the worked material. Hot compression tests of 7050 aluminum alloy was carried out on Gleeble1500D thermomechanical simulator to modeling multi-pass hot rolling process. Microstructure evolution features of the alloy deformed to a reduction up to 80% were investigated through OM, TEM and EBSD observations. DRX behavior of the alloy during hot compression was emphasized. Some evidence of continuous DRX can be found in the alloy deformed at different temperatures and reductions. The main nucleation mechanisms of DRX are subgrain coalescence and subgrain growth. However, static recrystallization takes place in the material during slow cooling after hot compression.

Soften Behavior of 7050 Aluminum Alloy during High Temperature Compression Deformation

2011 ◽  
Vol 109 ◽  
pp. 161-164
Author(s):  
Huie Hu ◽  
Xiao Dong Kong ◽  
Zhen Hai Shao
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Grain Boundary ◽  
Dynamic Recrystallization ◽  
Dynamic Recovery ◽  
Strain Rates ◽  
Compression Tests ◽  
7050 Aluminum Alloy ◽  
Subgrain Growth ◽  
Nucleation Mechanisms

Soften behavior of 7050 aluminum alloy was investigated by high temperature compression tests conducted at 460 °C with different strain rates of 0.1, 1, 10 and 100 s-1. The results show that all the volume fractions of recrystallized grain and substructed grain of the 7050 aluminum alloy deformed at 460 °C with different strain rates are higher than 35% and 20%, respectively. Dynamic recovery and dynamic recrystallization are primary soften mechanism of the 7050 aluminum alloy deformation at 460 °C, which is not sensitive to strain rate. The recryatallization nucleation mechanisms of the 7050 aluminum alloy deformed at 460 °C include in grain boundary arch, subgrain growth and subgrain merging.

MODELING AND SIMULATION OF DYNAMIC RECRYSTALLIZATION AND GRAIN GROWTH DURING HOT WORKING OF INCONEL 783 SUPERALLOY

2010 ◽  
Vol 17 (01) ◽  
pp. 105-109 ◽  
Author(s):  
JONG-TAEK YEOM ◽  
EUN JEOUNG JUNG ◽  
JEE HOON KIM ◽  
JEOUNG HAN KIM ◽  
JAE-KEUN HONG ◽  
...  
Keyword(s):  
Grain Growth ◽  
Compression Test ◽  
Microstructure Evolution ◽  
Optimization Technique ◽  
Hot Compression ◽  
Hot Working ◽  
Least Square ◽  
Isothermal Heat Treatment ◽  
Compression Tests ◽  
Hot Compression Test

In this study, the modeling of recrystallization and grain growth was investigated to predict the microstructure evolution during hot working of INCONEL 783 superalloy (Alloy 783). The recrystallization model was constructed on the basis of the Avrami formation. A least-square optimization technique was used to determine several important parameters within the model from isothermal heat treatment and hot compression test results. High temperature compression tests were carried out under different temperatures, strain rates and strain conditions. The model for describing the recrystallization and grain growth behaviors of Alloy 783 was implemented onto the user-subroutine of a commercial FE code. In order to demonstrate the reliability of the model, the microstructure evolution of Alloy 783 alloy during the hot compression test was simulated and was accorded well with the experimental results.

Mechanical Behavior and Microstructure Evolution of Mg-Gd-Y-Zn-Zr Alloy during Multipass Hot Compression Deformation

2016 ◽  
Vol 849 ◽  
pp. 186-195 ◽  
Author(s):  
Jian Min Yu ◽  
Xu Bin Li ◽  
Zhi Min Zhang ◽  
Qiang Wang ◽  
Yao Jin Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cast Alloy ◽  
Hardness Test ◽  
Hot Compression ◽  
Compression Tests ◽  
Softening Effect ◽  
Hot Compression Deformation ◽  
Compression Deformation ◽  
Multipass Deformation

The multi-pass hot compression deformation behavior of the cast alloy with the composition of Mg-13Gd-4Y-2Zn-0.6Zr, was investigated, and the four-pass compression tests were conducted at the temperatures ranging from 350°C to 500°C and strain rate 0.01 s-1. The experimental results showed that the alloys incurred different degrees of softening by multipass deformation. The microstructure evolution for the deformed alloy was investigated, the influence of the microstructure on the hardness properties of the alloy discussed. The tests reveal that dynamic recrystallization is not the main softening mechanism for this alloy; rather, kink deformation refines the grains to achieve the observed softening effect. The hardness test curve showed that the hardness increased gradually with an increasing number of deformation passes. The improvement of the main mechanical properties related to the strengthening by the grain refinement. In multipass deformation, the misorientation of the kink belt gradually increased,and refined the grains. On the other hand, the grain size of the eutectic phase at the grain boundary decreased with increase of deformation passes. In addition, the mechanical properties were improved by the distribution dispersion of tiny cuboidal particles and acicular-like phases in the matrix.

Recrystallization Behavior of 0.11% Ti-Added Complex Phase Steel during Hot Compression

2013 ◽  
Vol 762 ◽  
pp. 128-133 ◽  
Author(s):  
Mei Zhang ◽  
Chao Bin Huang ◽  
Wei Ming Zeng ◽  
Ren Yu Fu ◽  
Lin Li
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Kinetic Method ◽  
Hot Compression ◽  
Recrystallization Temperature ◽  
Recrystallization Process ◽  
Recrystallization Behavior ◽  
Compression Tests ◽  
Complex Phase ◽  
Austenite Grain

Double-hit isothermal deformation and multi-pass continuous cooling hot compression tests were carried out to study the recrystallization behavior of a 0.11 (in mass %) Ti-microalloyed complex phase (CP) steel. The influence of different deforming temperatures and holding times on microstructure evolution was investigated. The results showed that a pronounced austenite grain refinement after appropriate recrystallization process has been detected. The grain size decreases continuously from 176μm to 20μm after four-pass compression. It has been verified that non-crystallization temperature (Tnr) of the experimental steel is about 975°C under the deformation conditions. Based on the stress-strain curves, a kinetic method was established to predict the non-recrystallization temperature of the studied steel during nonisothermal continuous hot deformation.

The Enhanced Ability to Withstand Axial Hot Compression of Electropulsing-Assisted Ultrasonic Surface Rolling Process Treated Inconel 718

2019 ◽  
Vol 298 ◽  
pp. 69-74
Author(s):  
Zhi Yan Sun ◽  
Ti Min Hu ◽  
Shuai Ren ◽  
Bo Li
Keyword(s):  
Grain Boundaries ◽  
Compression Test ◽  
Inconel 718 ◽  
Rolling Process ◽  
Hot Compression ◽  
Compression Tests ◽  
Near Surface ◽  
Hot Compression Test ◽  
Study Results ◽  
Fine Microstructure

The ability to withstand axial hot compression at 700 °C of electropulsing-assisted ultrasonic surface rolling process (EUSRP) treated Inconel 718 was characterized by hot compression tests in this study. Results indicated that EUSRP induced ultra-fine microstructure on the near-surface regions of the sample and the formation of recrystallized ultra-fine grains in the near-surface regions was further promoted during hot compression test. In addition, a large number of nanoγ'' phases were precipitated on the broadened grain boundaries of the near-surface regions. In summary, EUSRP enhanced the ability to withstand axial hot compression of Inconel 718 at 700 °C.

scholarly journals Effect of Ultrasonic Surface Rolling Process on the Hot Compression Behavior of Inconel 718 Superalloy at 700 °C

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 658 ◽  
Author(s):  
Sun ◽  
Ren ◽  
Hu ◽  
Li
Keyword(s):  
Grain Boundaries ◽  
Inconel 718 ◽  
Volume Fraction ◽  
Rolling Process ◽  
Hot Compression ◽  
Compression Tests ◽  
Compression Process ◽  
Near Surface ◽  
Compression Behavior ◽  
Inconel 718 Superalloy

A series of hot compression tests at the temperature of 700 °C were applied to study the effect of the ultrasonic surface rolling process (USRP) on the hot compression behavior of Inconel 718 superalloy. The results indicated that the USRP-treated samples exhibited a better ability to withstand axial hot compression than the untreated samples. After the hot compression process, the size of the matrix grains was slightly decreased, and the volume fraction of ultra-fine recrystallized grains in the near-surface regions was increased for the USRP-treated samples. In addition, for USRP-treated samples, a large number of γ″ phases with size less than 100 nm were precipitated within the broadened grain boundaries in the near-surface regions rather than the inner grains. The enhanced ability to withstand axial compression at 700 °C for USRP-treated samples was related to the ultra-fine microstructure induced by USRP, combined with the precipitation of nano-γ″ phases within broadened grain boundaries and the increase of ultra-fine recrystallized grains in the near-surface regions during the hot compression process.

scholarly journals Investigation into Microstructure Evolution of Co–Ni–Cr–W–Based Superalloy During Hot Deformation

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Zhang ◽  
Baohong Zhu ◽  
Shuaishuai Wu ◽  
Shutian Tao
Keyword(s):  
Dynamic Recrystallization ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Electron Backscatter Diffraction ◽  
Strain Rates ◽  
Compression Tests ◽  
Continuous Dynamic Recrystallization ◽  
Nucleation Mechanisms ◽  
Ebsd Technique ◽  
Continuous Dynamic

Hot compression tests were conducted using a Gleeble 3500 thermomechanical simulator at temperatures ranging from 1,000 to 1,200°C with the strain rate ranging from 0.1 to 10 s−1. Electron backscatter diffraction (EBSD) technique was employed by investigating the microstructure evolution during hot deformation. Microstructure observations reveal that deformation temperatures and strain rates have a significant effect on the DRX process. It is found that the fraction and grain size of DRX increase with the decreasing deformation temperature, along with the increasing high-angle grain boundaries (HAGBs). The fraction of DRX first decreases and then increases with the increase of strain rates. It is noted that there are both the nucleation mechanisms of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) during the DRX process for Co–Ni–Cr–W–based superalloys. DDRX and CDRX are the primary and subsidiary nucleation mechanisms of DRX, respectively. It is also found that deformation temperatures and strain rates have almost no effect on the primary and subsidiary nucleation mechanisms of DRX. At the temperature above 1,150°C, the complete DRX occurred with the average grain sizes of about 25.32–29.01 μm. The homogeneity and refinement of microstructure can be obtained by selecting the suitable hot deformation parameters.

Microstructure Evolution and Change in Mechanical Properties of Medium Mn Steels during Thermomechanical Processing

2018 ◽  
Vol 941 ◽  
pp. 346-351
Author(s):  
Fei Fei Hou ◽  
Atsushi Ito ◽  
Yu Bai ◽  
Akinobu Shibata ◽  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Microstructure Evolution ◽  
Thermomechanical Processing ◽  
Phase Region ◽  
Hot Compression ◽  
Manganese Steel ◽  
Compression Tests ◽  
Static Conditions ◽  
Manganese Steels

Medium manganese steels are nowadays energetically investigated as the third generation advanced high strength steels (AHSS) because of their excellent balance between material cost and mechanical properties. However, the phase transformation and microstructure evolution in medium manganese steels during various heat treatments and thermomechanical processing are still unclear. The present study firstly examined kinetics of static phase transformation behavior and microstructural change in a 3Mn-0.1C medium manganese steel. Hot compression tests were also carried out to investigate the influences of high-temperature thermomechanical processing on the microstructure evolution. It was found that ferrite transformation was quite slow in static conditions but greatly accelerated by hot compression in (austenite and ferrite) two phase region. Dual phase microstructures composed of martensite and ferrite with ferrite grain sizes of 1~2 μm were obtained, which exhibited superior mechanical properties.

Microstructure Evolution in Nb-Ti Micro-Alloyed Steel during Hot Compression and Hot Rolling Simulation

2013 ◽  
Vol 395-396 ◽  
pp. 342-347
Author(s):  
Bin Shen ◽  
Song He Zhu ◽  
Heng Hua Zhang
Keyword(s):  
Microstructure Evolution ◽  
Hot Rolling ◽  
Mathematic Model ◽  
Rolling Process ◽  
Hot Compression ◽  
Alloyed Steel ◽  
Forming Process ◽  
Austenite Grain Size ◽  
Micro Alloyed Steel ◽  
Hot Rolled

Based on a improved mathematic model of predicting austenite grain size of hot rolled Nb-Ti micro-alloyed steel, a module for calculating microstructure evolution in the steel during hot-forming process was developed. To evaluate the recrystallization behavior according to the proposed model during plate multi-pass hot rolling, the multi-pass hot compression and its FE analysis in couple with the newly determined model were conducted. It indicated that the present models were capable of simulating the multi-pass hot compression and the actual multi-pass rolling process. After simulating an actual rolling process in factory by using the above models, evolution laws of microstructure were analyzed. Simulation results of microstructure had a good agreement with the measured ones.

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