Kinetics of Recrystallization and Grain Growth of Cold Rolled TWIP Steel

2010 ◽  
Vol 89-91 ◽  
pp. 153-158 ◽  
Author(s):  
F. de las Cuevas ◽  
Mónica Reis ◽  
A. Ferraiuolo ◽  
G. Pratolongo ◽  
L. Pentti Karjalainen ◽  
...  
Keyword(s):  
Grain Growth ◽  
Twip Steel ◽  
Growth Equation ◽  
Grain Sizes ◽  
Time Space ◽  
Cold Rolled ◽  
Hot Rolled ◽  
Kinetics Of ◽  
Temperature Time ◽  
Growth Experiments

Hot rolled, laboratory-cast, TWIP steel samples (5.4 mm thick) of 22% Mn - 0.6% C (in mass-%) were cold rolled to different reductions (from 40 % to 70 %) and subsequently isothermally annealed for various times at temperatures ranging from 450º C to 1100º C. The evolution of recrystallization and grain growth was followed by control of the softening kinetics complemented by metallographic, OIM and microtexture observations. A map of the recovery, recrystallization and grain growth in the temperature-time space was obtained. In all instances, the grain size at the end of recrystallization was very fine, D ≤ 2 µm and larger grain sizes were the result of grain growth. A range of grain sizes 2 µm ≤ D ≤ 50 µm was covered by the grain growth experiments. A phenomenological grain growth equation that is useful for the annealing control of this steel was derived from the measurements.

Texture Evolution during Grain Growth under the Influence of Mechanical Stresses

2005 ◽  
Vol 495-497 ◽  
pp. 1279-1284 ◽  
Author(s):  
Myrjam Winning
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Texture Evolution ◽  
Mechanical Stresses ◽  
Stress Fields ◽  
Grain Sizes ◽  
Purity Aluminium ◽  
High Purity Aluminium ◽  
Kinetics Of ◽  
Growth Experiments

In order to study the influence of mechanical stress fields on the kinetics and texture evolution of grain growth, experiments were performed on high purity aluminium. Samples were annealed under the influence of different mechanical stresses. The temporal evolutions of grain sizes and of macrotexture were analysed in ependence on the applied stress. The results show that mechanical stresses can change the kinetics of grain growth and slow down the increase in the grain size. Also effects on the texture evolution were observed and shall be discussed.

Low C High Mn Cold Rolled TWIP Steel: Kinetics of Isothermal Recrystallization

2012 ◽  
Vol 706-709 ◽  
pp. 2181-2186 ◽  
Author(s):  
Tulio M.F. Melo ◽  
Érica Ribeiro ◽  
Lorena Dutra ◽  
Dagoberto Brandão Santos
Keyword(s):  
Automobile Industry ◽  
Twip Steel ◽  
Volume Fraction ◽  
Microstructural Analysis ◽  
High Strength ◽  
Specific Weight ◽  
Carbon Steels ◽  
Cold Rolled ◽  
Increasing Demand ◽  
Kinetics Of

The increasing demand, mainly from the automobile industry, for materials which combine high strength, high ductility and low specific weight makes steels with the TWIP (TWinning Induced Plasticity) effect a promising material to meet these requirements. This work aimed to study the kinetics of isothermal recrystallization of a TWIP steel (C-0.06%, Mn-25%, Al-3%, Si-2%, and Ni-1%) after cold rolling. The steel was hot and cold-rolled and then annealed at 700°C with soaking times ranging from 10 to 7200 s. Microstructural analysis was performed using light (LM) and scanning electron microscopy (SEM). Furthermore, quantitative metallography was performed in order to evaluate the recrystallized volume fraction and grain size. A JMAK based model was applied to describe the nucleation grain growth process. The restoration of the steel was also evaluated by microhardness tests. A complete recrystallization after 7200 s at 700°C was observed. It was found that with increasing annealing times, the recrystallized volume fraction also increases, while the nucleation and growth rates decrease, in agreement with the results for plain carbon steels.

Effects of Solubility Limit and the Presence of Ultra-Fine Al6Fe on the Kinetics of Grain Growth in Dilute Al-Fe Alloys

2007 ◽  
Vol 550 ◽  
pp. 339-344 ◽  
Author(s):  
Shigeo Saimoto ◽  
Hai Ou Jin
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Grain Growth ◽  
Solubility Limit ◽  
Rolled Sheet ◽  
Migration Rates ◽  
Cold Rolled ◽  
Fe Alloys ◽  
Grain Growth Kinetics ◽  
Kinetics Of

A nominally pure Al slab was thermo-mechanically treated to result in a near random texture of 90 m grain size. Subsequent cold rolling with intermediate anneals at 230, 275, and 300°C reduced the Fe solute to near equilibrium compositions below 0.5 ppm atomic. The final cold rolled sheet continuously recrystallized; grain growth of this structure is reported. A grain-growth kinetics mapping was generated, correlating the parameters of Fe-in-Al solubility limit, Fe diffusivities in the grain boundaries and the Al lattice and the activation energies for migration rates.

scholarly journals Evaluation of the Austenitic Grain Growth by Thermoelectric Power Measurements

2004 ◽  
Vol 467-470 ◽  
pp. 863-868 ◽  
Author(s):  
Carlos Capdevila ◽  
Tommy De Cock ◽  
Francisca García Caballero ◽  
Carlos García-Mateo ◽  
Carlos García de Andrés
Keyword(s):  
Thermoelectric Power ◽  
Grain Growth ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Grain Sizes ◽  
Different Temperatures ◽  
Cold Rolled ◽  
The Mean ◽  
Power Measurements

The influence of the deformation grade on the recrystallised grain size has been studied in the AISI 304 stainless steel. Therefore, cold rolled samples of this material with reductions varying between 30% and 80% were annealed at different temperatures and subsequently quenched. The mean austenitic grain sizes were measured and compared. Moreover, the correlation between the variation of the thermoelectric power and the grain growth was investigated for each degree of prior deformation.

β Grain Growth Kinetics of Hot-Rolled TB-13 Alloy

2011 ◽  
Vol 689 ◽  
pp. 472-478 ◽  
Author(s):  
Yue Fei ◽  
Bin Tang ◽  
Hui Chang ◽  
Zhi Shou Zhu ◽  
Zhong Bo Zhou ◽  
...  
Keyword(s):  
Activation Energy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Fine Grained ◽  
Solution Treated ◽  
Grain Growth Kinetics ◽  
Hot Rolled ◽  
Kinetics Of

A study on the kinetics of β grain growth of a fine-grained, hot-rolled TB-13 alloy was carried out by isochronal and isothermal solution treatments. The grain size of the as-rolled and as-solution-treated samples was determined by metallographic observation using the linear intercept method. The kinetic equations and the Arrhenius-type equation were applied to calculate the β grain growth exponent and the activation energy for β grain growth at special temperatures. The results showed that the β grain growth rate decreased with elongating solution treated time, but increased with increasing solution treated temperature. The β grain growth exponents (n) were 0.394, 0.403 and 0.406 during the solution treated temperatures at 1103K, 1153K and 1203K, respectively. The values of n increased with increasing solution treated temperature and the determined activation energy (Qm) for β grain growth after holding for 0.5h at 1103K-1203K was around 156KJ/mol.

Effect of Magnetic Field Processing on Recrystallization and Grain Growth

2012 ◽  
Vol 706-709 ◽  
pp. 2806-2811 ◽  
Author(s):  
I. Salvatori
Keyword(s):  
Magnetic Field ◽  
Grain Growth ◽  
High Magnetic Field ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Retarding Effect ◽  
Cold Rolled ◽  
Kinetics Of

In this paper the recrystallisation kinetics of cold rolled strips as a function of magnetic field intensity has been studied on a Fe-0.05C-1.5Mn alloy. The retarding effect on recrystallisation due to the application of a magnetic field on samples treated with magnetic field up to 10T, has been experimentally confirmed. The effect was more evident for high magnetic field and for long annealing times. In addition, a small retarding effect of magnetic field on grain growth has been noticed.

scholarly journals Influence of Finite Mobilities of Triple Junctions on the Grain Morphology and Kinetics of Grain Growth

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 185
Author(s):  
Ernst Gamsjäger ◽  
Boris Gschöpf ◽  
Jiří Svoboda
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Triple Junction ◽  
Cell Model ◽  
Grain Morphology ◽  
Triple Junctions ◽  
Grain Sizes ◽  
Heat Treated ◽  
Niobium Microalloyed Steel ◽  
Kinetics Of

Grain boundary networks composed of equal microstructural elements were investigated in a recent paper. In this work a more complicated artificial grain topology consisting of one four-sided, two six-sided and one eight-sided grain is designed to further investigate the influence of grain boundary and triple junction mobilities on the kinetics of the system in more detail. Depending on the value of the equal mobility of all triple junctions, the initially square-shaped four-sided grain changes its shape to become more or less rectangular. This indicates that the grain morphology is influenced by the value of the mobility of the triple junctions. It is also demonstrated that a grain arrangement with low mobility triple junctions controlling the kinetics of grain growth enhances growth of the large eight-sided grains. In addition, grain growth is investigated for different values of mobilities of triple junctions and grain boundaries. A strong elongation of several grains is predicted by the modeling results for reduced mobilities of the microstructural grain boundary elements. The two-dimensional modeling results are compared to micrographs of a heat-treated titanium niobium microalloyed steel. This feature, namely the evolution of elongated grains, is observed in the micrograph due to the pinning effect of (Ti, Nb)C precipitates at elevated soaking temperatures of around 1100 °C. Furthermore, the experiments show that a broader distribution of the grain sizes occur at 1100 °C compared to soaking temperatures, where pinning due to precipitates plays a less prominent role. A widening of the distribution of the grain sizes for small triple junction mobilities is also predicted by the unit cell model.

Hall-Petch Relationship of a TWIP Steel

2009 ◽  
Vol 423 ◽  
pp. 147-152 ◽  
Author(s):  
F. de las Cuevas ◽  
Mónica Reis ◽  
A. Ferraiuolo ◽  
G. Pratolongo ◽  
L. Pentti Karjalainen ◽  
...  
Keyword(s):  
Twip Steel ◽  
Tensile Tests ◽  
Grain Sizes ◽  
Strain Behaviour ◽  
Wide Range ◽  
Work Hardening Rate ◽  
Twip Steels ◽  
Complete Recrystallization ◽  
Cold Rolled ◽  
Relationship Of

The grain size dependence of the tensile properties of a TWIP steel has been determined for a wide range of grain sizes obtained by grain growth after complete recrystallization of cold rolled material. The near-linear stress-strain behaviour typical of either TWIP steels or other materials that deform by twinning has been observed, the work hardening rate being larger for the smaller grain sizes. The Hall-Petch slope increases as a function of strain, from 350 MPa μm1/2 for the yield stress to 630 MPa μm1/2 for the maximum uniform strain in the tensile tests, ε  0.40. Profuse twinning is observed in deformed specimens by means of FIB-ISE.

scholarly journals On the Grain Growth Kinetics of a Low Density Steel

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 997 ◽  
Author(s):  
Daniel M. Field ◽  
Krista R. Limmer ◽  
Billy C. Hornbuckle
Keyword(s):  
Grain Growth ◽  
Growth Kinetics ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Low Density ◽  
Grain Sizes ◽  
Mean Linear Intercept ◽  
Grain Growth Kinetics ◽  
Kinetics Of

The grain growth kinetics of an age-hardenable Fe-Mn-Al-C steel were investigated. Kinetics of grain growth were determined between 1173 and 1348 K (900–1075 °C) to obtain a range of grain sizes from 30 to 475 μm. It was found that grain growth was negligible at 1173 K (900 °C) for times up to 15 h. The activation energy for grain growth was found to be 467 kJ/mol. The hardness and mean linear intercept (L3) were correlated to follow a traditional Hall-Petch relationship. Tensile properties of the alloy were determined after various solution treatments performed for 2 h followed by water quenching. Tensile strength increased from 810 to 960 MPa and ductility was reduced from 80 to 60% as the grain size decreased from 200 μm to 30 μm as grain coarsening was mitigated by lowering the solution treatment temperature.

Effect of Cooling Rate and Nb Composition on Non-Isothermal Austenite Grain Growth Kinetics in Nb-HSLA Steel during Hot Rolling

2012 ◽  
Vol 479-481 ◽  
pp. 414-420 ◽  
Author(s):  
Myrna Ariati ◽  
Azwar Manaf ◽  
Eddy S. Siradj
Keyword(s):  
Grain Size ◽  
Cooling Rate ◽  
Grain Growth ◽  
Hot Rolling ◽  
Isothermal Condition ◽  
Growth Equation ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Hot Rolled ◽  
Austenite Grain Growth

Abstract. The strength of a final product of steel is affected by its final austenite grain size.Almost applied models for grain growth based on Beck and Sellars equation , which has the isothermal condition assumption; whilst most of the materials processing take place under non-isothermal condition. The purpose of this research is to find the effect of Nb and cooling rate to the austenite grain growth model of HSLA-Nb steel to predict the Austenite grain size after hot rolling process in non-isothermal condition .The two composition of 0.019 and 0.056% Nb of HSLA-Nb was hot-rolled about 0.3-0.4 deformation at a temperature of 900-11000 C, followed by cooling rate of 7-11 0 C/s, in a time period of 25-40 second, and quenched by using water jetspray. Austenite final grain size was measured . The work shows that the higher Nb content of steel with higher cooling rate will reduce the final austenite grain size . It was also found that the new non-isothermal austenite grain growth after hot-rolled illustrated as a function of cooling rate,which obtained by modifying the previous established model by a cooling rate parameter 1/Crm, and it was more precision compared to previous grain growth equation.

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