scholarly journals The Research on Recrystallization Behaviors and Mechanism of a Medium-Density Ni-Based Alloy

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 137
Author(s):  
Kai Feng ◽  
Xiaxu Huang ◽  
Rui Wang ◽  
Wenli Xue ◽  
Yilei Fu ◽  
...  
Keyword(s):  
Early Stage ◽  
Texture Evolution ◽  
Great Influence ◽  
Recrystallization Annealing ◽  
Recrystallization Process ◽  
Recrystallization Behavior ◽  
Size Change ◽  
Recrystallization Mechanism ◽  
Annealing Twins ◽  
Complete Recrystallization

Revealing the recrystallization behavior and mechanism of this new alloy is of great significance to subsequent research. In this study, the Ni-36.6W-15Co ternary medium heavy alloy was solution-treated at 1100–1200 °C for different lengths of time. The grain size change, microstructure and texture evolution as well as twin development during recrystallization annealing were analyzed using SEM, EBSD and TEM techniques. The study found that complete recrystallization occurs at 1150 °C/60 min. In addition, it takes a longer amount of time for complete recrystallization to occur at 1100 °C. The value of the activation energy Q1 of the studied alloys is 701 kJ/mol and the recrystallization process is relatively slow. By comparing the changes of microstructure and texture with superalloys, it is found that the recrystallization mechanism of the studied alloy is different from that of the superalloy. The development of annealing twins has a great influence on the recrystallization behavior and mechanism. The results show that the twin mechanism is considered as the dominant recrystallization mechanism of the studied alloy, although the formation and development of sub-grains appear in the early stage of recrystallization.

Microstructure and Texture Evolution Law of Ti-IF Steel for Extra Deep Drawing during Batch Annealing Process

2013 ◽  
Vol 873 ◽  
pp. 42-47
Author(s):  
Zheng Bing Meng ◽  
Lang He ◽  
Guang Liang Wu ◽  
Xin Bin Liu ◽  
Chao Yang Zhou
Keyword(s):  
Deep Drawing ◽  
Early Stage ◽  
Texture Evolution ◽  
Annealing Process ◽  
Recrystallization Temperature ◽  
Recrystallization Annealing ◽  
Recrystallization Process ◽  
If Steel ◽  
Hardness Tester ◽  
Batch Annealing

The variation of microstructure of Ti-IF steel of extra deep drawing grade, which having a 83%cold-rolled deformation under simulated batch annealing process at temperature ranging from 480°C to 750°C, was studied by using optical microscopy, X-ray diffraction (XRD) and metallographic micro-hardness tester. The evolution of texture during the recrystallization process was analyzed by Orientation Density Function (ODF). The results show that, the recrystallization temperature of experimental steel is 620-630°C, and the recrystallization process can be accomplished within 1h at660°C. Four major textures after cold rolling are observed as follows,{001}<110>, {111}<110>, {111}<112> and {112}<110>, respectively. At the early stage of recrystallization annealing, texture evolves from {111} toγ-{111}, which is quite beneficial to achieve high deep drawing performance,the texture {001}<110> and {112}<110> change marginally. as the annealing temperature rises up to 720°C, texture {001}<110> and {112}<110> change into fiber textureγ-{111}. After annealing,{111}<112> and {111}<110> textures become the two main types.

Precipitation Behavior of Warm-Rolled Ti-Stabilized Interstitial-Free (IF) Steel Sheets

2007 ◽  
Vol 353-358 ◽  
pp. 1653-1656 ◽  
Author(s):  
Fu Tao Han ◽  
Zuo Cheng Wang ◽  
Cai Nian Jing ◽  
Wen Ping Zhang
Keyword(s):  
Texture Evolution ◽  
Great Influence ◽  
High Strength ◽  
Recrystallization Annealing ◽  
Interstitial Free ◽  
If Steel ◽  
Precipitation Behavior ◽  
Steel Sheets ◽  
Energy Dispersion Spectrometer ◽  
Transmission Electron

Precipitates have great influence on the recrystallization, texture evolution and thus the final mechanical properties of the Interstitial-Free (IF) steel sheets, however, very few studies have dealt with the precipitation behavior of IF steels warm rolled in ferrite region. In the present work, the precipitate characteristics (type, morphology, size and amount) of warm-rolled ordinary Ti-stabilized Interstitial-Free (Ti-IF) steel and p-added high-strength Ti-IF steel were investigated by Transmission Electron Microscope (TEM) and Energy Dispersion Spectrometer (EDS). The results show that most precipitates in warm-rolled ordinary Ti-IF steels are TiN, TiS, Ti4C2S2 and TiC. Besides these precipitates, a great amount of FeTiP precipitates exist in warm-rolled P-added high-strength Ti-IF steel. The precipitation of FeTiP retards the migration of grain boundary in the recrystallization annealing, so the {111} texture and thus deep drawability of warm-rolled high-strength Ti-IF steel is deteriorated.

scholarly journals Texture Evolution During the Drawing of Low Carbon Steel

1994 ◽  
Vol 22 (4) ◽  
pp. 261-278 ◽  
Author(s):  
C. Schuman ◽  
C. Esling ◽  
M. J. Philippe ◽  
M. Hergesheimer ◽  
M. Jallon ◽  
...  
Keyword(s):  
Deformation Rate ◽  
Early Stage ◽  
Texture Evolution ◽  
Reduction Rate ◽  
Carbon Steels ◽  
Texture Gradient ◽  
Interstitial Free ◽  
Low Carbon ◽  
Fibre Texture ◽  
Drawing Direction

This study deals with the texture evolution during drawing of interstitial-free low carbon steels under different conditions to study the possible influence of the drawing direction, deformation rate and metal/die friction coefficient. The drawing has been carried out without intermediary annealing, with constant die angle and deformation rate per pass. In all cases, a 〈110〉 fibre texture has been observed at the early stage of deformation (a few percents). The drawing direction, whether alternate or unidirectional, has little effect on texture. Slight differences only in the intensity of peaks on pole figures (PFs) are noted. Alternate drawing leads to higher drawing limits. The grain size affects both the texture and the mechanical properties, which are improved by fine grains. For industrial drawing, i.e. at a high deformation rate, no texture gradient has been clearly observed. Nevertheless, slight differences have been noted in the PF intensities, with generally a slightly sharper texture in the core, compared to the surface. The microhardness tests show no hardness gradient. In slow drawing (low deformation rate), there is a weak texture gradient which disappears at larger deformation. In order to visualize the influence of the metal/die friction, we used a material covered with copper. Results show that at a given reduction rate, the material covered with copper shows peak intensities on the (110) PF which are half these of a material drawn under conventional conditions. The drawing textures of BCC materials always present a 〈110〉 fibre texture. A modeling of the texture evolution during drawing has also been carried out using the Taylor model.

scholarly journals Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Wakshum M. Tucho ◽  
Vidar Hansen
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Additive Manufacturing ◽  
Inconel 718 ◽  
Solution Heat Treatment ◽  
Hold Time ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Annealing Twins ◽  
Complete Recrystallization

The widely adopted temperature for solid solution heat treatment (ST) for the conventionally fabricated Inconel 718 is 1100 °C for a hold time of 1 h or less. This ST scheme is, however, not enough to dissolve Laves and annihilate dislocations completely in samples fabricated with Laser metal powder bed fusion (L-PBF) additive manufacturing (AM)-Inconel 718. Despite this, the highest hardness obtained after aging for ST temperatures (970–1250 °C) is at 1100 °C/1 as we have ascertained in our previous studies. The unreleased residual stresses in the retained lattice defects potentially affect other properties of the material. Hence, this work aims to investigate if a longer hold time of ST at 1100 °C will lead to complete recrystallization while maintaining the hardness after aging or not. For this study, L-PBF-Inconel 718 samples were ST at 1100 °C at various hold times (1, 3, 6, 9, 16, or 24 h) and aged to study the effects on microstructure and hardness. In addition, a sample was directly aged to study the effects of bypassing ST. The samples (ST and aged) gain hardness by 43–49%. The high density of annealing twins evolved during 3 h of ST and only slightly varies for longer ST.

Recrystallization Characteristics of Ti-50.9at%Ni Alloy Processed by Equal Channel Angular Extrusion

2007 ◽  
Vol 26-28 ◽  
pp. 385-388 ◽  
Author(s):  
Zhi Guo Fan ◽  
Chao Ying Xie
Keyword(s):  
High Temperature ◽  
Optical Microscopy ◽  
Equal Channel Angular Extrusion ◽  
Recrystallization Process ◽  
Recrystallization Behavior ◽  
Ni Alloy ◽  
Coarse Grains ◽  
Angular Extrusion

The initial coarse grains of Ti-50.9at%Ni alloy were refined into submicron grains, small than 0.5 um in size, after eight passes Equal Channel Angular Extrusion (ECAE) at 500°C. Optical microscopy and high temperature DSC tests were applied to investigate recrystallization behavior. It is found that the recrystallization start (Rs) and recrystallization peak (Rp) temperatures of Ti-50.9at%Ni specimens processed by eight passes ECAE are lower than that of the samples processed by one pass ECAE. Ti-50.9at%Ni specimens processed by eight passes ECAE with submicron grains are characterized by higher stability and need less energy to finish recrystallization process.

scholarly journals Microstructure and Texture Evolution of Mg-Gd-Y-Zr Alloy during Reciprocating Upsetting-Extrusion

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4932
Author(s):  
Guoqin Wu ◽  
Jianmin Yu ◽  
Leichen Jia ◽  
Wenlong Xu ◽  
Beibei Dong ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Basal Plane ◽  
Deformation Process ◽  
Texture Evolution ◽  
Extrusion Process ◽  
Fiber Texture ◽  
Recrystallization Process ◽  
Application Range ◽  
Continuous Dynamic Recrystallization ◽  
Cumulative Strain

Reciprocating Upsetting-Extrusion (RUE) deformation process can significantly refine the grains size and weaken the basal plane texture by applying a large cumulative strain to the alloy, which is of great significance to weaken the anisotropy of magnesium (Mg) alloys and increase the application range. In this paper, the Mg-8.27Gd-3.18Y-0.43Zr (wt %) alloy was subjected to isothermal multi-passes RUE. The microstructure and texture evolution, crystal orientation-dependent deformation mechanism of the alloy after deformation were investigated. The results clearly show that with the increase of RUE process, the grains are significantly refined through continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) mechanisms, the uniformity of the microstructure is improved, and the texture intensity is reduced. At the same time, a large number of particle phases are dynamically precipitated during the deformation process, promoting grain refinement by the particle-stimulated nucleation (PSN) mechanism. The typical [10-10] fiber texture is produced after one pass due to the basal plane of the deformed grains with a relatively high proportion is gradually parallel to the ED during extrusion process. However, the texture concentration is reduced compared with the traditional extrusion deformation, indicating that the upsetting deformation has a certain delay effect on the subsequent extrusion texture generation. After three or four passes deformation, the grain orientation is randomized due to the continuous progress of the dynamic recrystallization process.

scholarly journals Study of the Dynamic Recrystallization Process of the Inconel625 Alloy at a High Strain Rate

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 510 ◽  
Author(s):  
Zhi Jia ◽  
Zexi Gao ◽  
Jinjin Ji ◽  
Dexue Liu ◽  
Tingbiao Guo ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
True Strain ◽  
Recrystallization Process ◽  
Compression Process

High-temperature compression and electron backscatter diffraction (EBSD) techniques were used in a systematic investigation of the dynamic recrystallization (DRX) behavior and texture evolution of the Inconel625 alloy. The true stress–true strain curves and the constitutive equation of Inconel625 were obtained at temperatures ranging from 900 to 1200 °C and strain rates of 10, 1, 0.1, and 0.01 s−1. The adiabatic heating effect was observed during the hot compression process. At a high strain rate, as the temperature increased, the grains initially refined and then grew, and the proportion of high-angle grain boundaries increased. The volume fraction of the dynamic recrystallization increased. Most of the grains were randomly distributed and the proportion of recrystallized texture components first increased and then decreased. Complete dynamic recrystallization occurred at 1100 °C, where the recrystallized volume fraction and the random distribution ratios of grains reached a maximum. This study indicated that the dynamic recrystallization mechanism of the Inconel625 alloy at a high strain rate included continuous dynamic recrystallization with subgrain merging and rotation, and discontinuous dynamic recrystallization with bulging grain boundary induced by twinning. The latter mechanism was less dominant.

Effect of Hot-Rolled Microstructure on the Recrystallization Texture of Cold-Rolled Non-Oriented Electrical Steel

2011 ◽  
Vol 298 ◽  
pp. 203-208 ◽  
Author(s):  
Zi Li Jin ◽  
Wei Li ◽  
Yi Ming Li
Keyword(s):  
Cold Rolling ◽  
Electrical Steel ◽  
Texture Evolution ◽  
Steel Strip ◽  
Silicon Steel ◽  
Grain Structure ◽  
Recrystallization Annealing ◽  
Rolled Sheet ◽  
Cold Rolled ◽  
Hot Rolled

With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory，to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110}<UVW> texture components was enhanced and {100}<uwv> texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.

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