scholarly journals Influence of Plastic Deformation on Microstructural Evolution of 100Cr6 Bearing Ring in Hot Ring Rolling

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4355
Author(s):  
Guanghua Zhou ◽  
Wenting Wei ◽  
Qinglong Liu
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Microstructural Evolution ◽  
Vickers Hardness ◽  
Microstructural Characterization ◽  
Lamellar Spacing ◽  
Rolling Process ◽  
Rolling Reduction ◽  
Ring Rolling ◽  
Bearing Rings

The hot ring rolling technology as the crucial procedure for the manufacture of bearing rings plays an important role in determining the final microstructure of bearing rings. In this work, the influence of the hot ring rolling process on the microstructural evolution of 100Cr6 bearing rings was investigated using a three-dimensional (3D) numerical model and microstructural characterization. It was found that the significant microstructural refinement occurs at the different regions of the rings. However, owing to the non-uniform plastic deformation of hot rolling, the refinement rate of grain size and decrease of pearlite lamellar spacing (PLS) also showed uniformity at different regions of the rings. Furthermore, the degree of grain refinement had been limited with the increase of rolling reduction. Due to the refined grain size and decreased PLS, the Vickers hardness increased with the increase of rolling reduction. Moreover, the Vickers hardness from the outer surface to the inner surface of the ring is asymmetrical u-shaped, which had the law of lower hardness in the center area and higher hardness on the surface.

Microstructural Evolution in Partially Homogenized AZ91 Alloy during Hot Rolling and Interpass Annealing

2012 ◽  
Vol 626 ◽  
pp. 445-448 ◽  
Author(s):  
Mahmoud Reza Ghandehari Ferdowsi ◽  
Mohammad Mazinani ◽  
Gholam Reza Ebrahimi
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Dynamic Recrystallization ◽  
Microstructural Evolution ◽  
Hot Rolling ◽  
Solution Treatment ◽  
Rolling Process ◽  
Az91 Alloy ◽  
Mean Grain Size ◽  
In The Beginning

The as-cast AZ91 Mg alloy ingot with mean grain size of 98 μm after solution treatment was subjected to plastic deformation by multi-pass hot rolling. The process facilitated steady grain refinement by dynamic recrystallization with increasing rolling passes, and the final grain size was reduced to 6.4 μm by 4 rolling passes. Optical microscopy demonstrated that in the beginning of the rolling process twin DRX was the major dynamic recrystallization mechanism. In contrast, in 3rdand 4thpasses of rolling new grains nucleated at grain boundaries, due to low grain size of the alloy.

Application of a Material Model to Predict Rolling Forces and Microstructure during a Hot Ring Rolling Process

2013 ◽  
Vol 762 ◽  
pp. 354-359 ◽  
Author(s):  
Thomas Henke ◽  
Gerhard Hirt ◽  
Markus Bambach
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Rolling Force ◽  
Flow Behavior ◽  
Rolling Process ◽  
Ring Rolling ◽  
Experimental Investigations ◽  
Forming Process ◽  
Ring Geometry ◽  
Ring Rolling Process

Ring rolling is an incremental bulk forming process. Hence, the process consists of a large number of alternating deformations and dwell steps. For accurate calculations of material flow and thus ring geometry and rolling forces in hot ring rolling processes, it seems necessary to consider material softening due to static and post dynamic recrystallization which could occur between two deformation steps. In addition, due to the large number of cycles, the modeling results, especially the prediction of grain size, can easily be affected by uncertainties in the input data. However, for small rings and ring material with slow recrystallization kinetics, the interpass times can be short compared to the softening kinetics and the effect of softening can be so small, that microstructure evolution and the description of the materials flow behavior can be de-coupled. In this paper, a semi-empirical JMAK-based model for a stainless steel (1.4301/ X5CrNi18-9/ AISI304) is presented and evaluated by the use of experiments and other investigations published in [1],[2]. Finite Element (FE) simulations of a ring rolling process with a high number of ring revolutions and thus multiple, incremental forming steps were conducted based on ring rolling experiments. The FE simulation results were validated with the experimentally derived rolling force and evolution of ring diameter. The microstructure evolution was calculated in a post processing step considering the investigated evolution of strain and temperature. In this calculation the interrelations between the fraction of dynamically recrystallized microstructure, the evolution of post-dynamically recrystallized microstructure and the final grain size have been considered. Both, the calculated final microstructure and the evolution of rolling force and ring geometry calculated stand in good agreement with the experimental investigations.

scholarly journals Studying Grain Boundary Strengthening by Dislocation-Based Strain Gradient Crystal Plasticity Coupled with a Multi-Phase-Field Model

2019 ◽  
Author(s):  
Waseem Amin ◽  
Muhammad Adil Ali ◽  
Napat Vajragupta ◽  
Alexander Hartmaier
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Microstructural Evolution ◽  
Crystal Plasticity ◽  
Phase Field ◽  
Strain Gradient ◽  
Mechanical Response ◽  
Functional Dependence ◽  
Initial State ◽  
Computational Materials

One ambitious objective of Integrated Computational Materials Engineering (ICME) is to shorten the materials development cycle by using computational materials simulation techniques at different length scales. In this regard, the most important aspects are the prediction of the microstructural evolution during material processing and the understanding of the contributions of microstructural features to the mechanical response of the materials. One possible solution to such a challenge is to apply the Phase Field (PF) method because it can predict the microstructural evolution under the influence of different internal or external stimuli, including deformation. To accomplish this, it is necessary to take into account plasticity or, specifically, non-homogeneous plastic deformation, which is particularly important for investigating the size effects in materials emerging at the micron length scale. In this work, we present quasi-2D simulations of plastic deformation in a face centred cubic system in a finite strain formulation. Our model consists of dislocation-based strain gradient crystal plasticity implemented into a PF code. We apply this model to study the influence of grain size on the mechanical behavior of polycrystals, which includes dislocation storage and annihilation. Furthermore, the initial state of the material before deformation is also considered. The results show that a dislocation-based strain gradient crystal plasticity model can capture the Hall-Petch effect in many aspects. The model reproduced the correct functional dependence of the flow stress of the polycrystal on grain size without assigning any special properties to the grain boundaries. However, the predicted Hall-Petch coefficients are significantly smaller than those found typically in experiments. In any case, we found a good qualitative agreement between our findings and experimental results.

scholarly journals Studying Grain Boundary Strengthening by Dislocation-Based Strain Gradient Crystal Plasticity Coupled with a Multi-Phase-Field Model

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2977 ◽  
Author(s):  
Waseem Amin ◽  
Muhammad Adil Ali ◽  
Napat Vajragupta ◽  
Alexander Hartmaier
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Microstructural Evolution ◽  
Crystal Plasticity ◽  
Phase Field ◽  
Strain Gradient ◽  
Mechanical Response ◽  
Functional Dependence ◽  
Initial State ◽  
Computational Materials

One ambitious objective of Integrated Computational Materials Engineering (ICME) is to shorten the materials development cycle by using computational materials simulation techniques at different length scales. In this regard, the most important aspects are the prediction of the microstructural evolution during material processing and the understanding of the contributions of microstructural features to the mechanical response of the materials. One possible solution to such a challenge is to apply the Phase Field (PF) method because it can predict the microstructural evolution under the influence of different internal or external stimuli, including deformation. To accomplish this, it is necessary to take into account plasticity or, specifically, non-homogeneous plastic deformation, which is particularly important for investigating the size effects in materials emerging at the micron length scale. In this work, we present quasi-2D simulations of plastic deformation in a face centred cubic system using a finite strain formulation. Our model consists of dislocation-based strain gradient crystal plasticity implemented into a PF code. We apply this model to study the influence of grain size on the mechanical behavior of polycrystals, which includes dislocation storage and annihilation. Furthermore, the initial state of the material before deformation is also considered. The results show that a dislocation-based strain gradient crystal plasticity model can capture the Hall-Petch effect in many aspects. The model reproduced the correct functional dependence of the flow stress of the polycrystal on grain size without assigning any special properties to the grain boundaries. However, the predicted Hall-Petch coefficients are significantly smaller than those found typically in experiments. In any case, we found a good qualitative agreement between our findings and experimental results.

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.

scholarly journals The Effects of Rolling Deformation and Annealing Treatment on Damping Capacity of 1200 Aluminium Alloy

2015 ◽  
Vol 819 ◽  
pp. 20-24
Author(s):  
Mohd Noor Mazlee ◽  
Shamsul Baharin Jamaludin ◽  
Y. Yasmin ◽  
Shaiful Rizam Shamsudin ◽  
M.S. Risby ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Aluminium Alloy ◽  
Microstructural Evolution ◽  
Rolling Direction ◽  
Annealing Treatment ◽  
Rolling Reduction ◽  
Damping Capacity ◽  
Percent Reduction ◽  
Rolling Deformation

Annealing treatment is an important step of rolling deformation that contributes to microstructural evolution and leads to the significant changes in damping capacity. Damping capacities were analyzed in the parallel to rolling direction at 1 and 10 Hz respectively. It was found that severe plastic deformation at 40 percent reduction has lower damping capacity compared to that of 30 percent and 20 percent reductions respectively. The microstructural results show that the grains of as rolled alloys were changed to almost equiaxed structures after a rolling reduction at 40 percent reduction.

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 Microstructural Characterization of Nb-Al Base ODS Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 436-439 ◽  
Author(s):  
Shigeharu Ukai ◽  
Akinobu Minami ◽  
Shigenari Hayashi ◽  
Norihito Sakaguchi ◽  
Seiji Miura
Keyword(s):  
Solid Solution ◽  
Plastic Deformation ◽  
Grain Size ◽  
Microstructural Characterization ◽  
Dual Phase ◽  
Mechanically Alloyed ◽  
Oxide Particles ◽  
Ods Alloys ◽  
Nb3al Compound

Nb, Al and Y2O3 powders were mechanically alloyed together with 5 wt% stearic acid. The heavy plastic deformation of the powders by mechanical alloying led significant hardening to 970 Hv and the reduced grain size to 10 nm. Nb-Al base ODS alloys consolidated by HIP at 1500 °C and 150 MPa for 0.5 h gave the dual phase of Nb solid solution and Nb3Al compound. The oxide particles are of the hexagonal type YAlO3 (YAH), with the size of 50 nm to 200 nm. The high-temperature ductility at 1200 °C and capability of the grain growth at 2000 °C were confirmed.

Process Design Concepts for the Production of Ultrafine Grained Steels through Multi-Pass Warm Rolling: Bridging Science and Technology

2011 ◽  
Vol 683 ◽  
pp. 225-231
Author(s):  
S.V.S. Narayana Murty ◽  
Shiro Torizuka
Keyword(s):  
Grain Size ◽  
Microstructural Evolution ◽  
Science And Technology ◽  
Compressive Strain ◽  
Rolling Process ◽  
Warm Deformation ◽  
Hollomon Parameter ◽  
Single Pass ◽  
Ultrafine Grained ◽  
Z Parameter

Steel bars having a cross section of 18mm square with uniform distribution of ultrafine ferrite grains were produced through a multi-pass warm caliber rolling process in a 0.15%C-0.3%Si-1.5%Mn steel. The average ferrite grain sizes of 0.43μ m, 0.70μ m and 1.2 μ m were obtained in the isothermal warm caliber rolling processes at 773K, 823K and 873K respectively. Even though caliber rolling results in inhomogeneous strain distribution, multi-pass caliber rolling to large cumulated strains of 2 or 3 can be uniformly introduced in to the bar samples. Strain accumulation due to the multi-pass warm deformations was confirmed by comparing microstructural evolution through the multi-pass deformations with that of single pass deformation. The size of ultrafine grains formed through warm deformation was found to depend on the Zener-Hollomon parameter. The similarity of the microstructural evolution with single pass deformation reveals that the multi-pass warm deformation is an effective method to obtain ultrafine grained ferrite structure in bulk materials. It is proposed that compressive strain-Z parameter plots along with grain size-Z parameter plots help in establishing the processing conditions for obtaining products with a desired microstructure and grain size. Finally, such “processing maps” developed for a variety of materials serve useful purpose in bridging the science and technology of developing bulk ultrafine grained materials in semi-finished / finished products.

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