The Effect of Final Annealing Heating Rate on Abnormal Grain Growth in a Fe-3.5%Si Steel

2016 ◽  
Vol 879 ◽  
pp. 350-355
Author(s):  
Fatayalkadri Citrawati ◽  
Md Zakaria Quadir ◽  
Paul Munroe
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Rapid Heating ◽  
Secondary Recrystallization ◽  
Recrystallization Annealing ◽  
Final Annealing

In this study the effects of heating rate on the sharpness and size of Goss oriented ({110}<001>) grains during secondary recrystallization annealing at 900 °C was observed. The results show that, at the same annealing temperature, rapid heating of the samples to this temperature generates a higher drag force compared to a slower heating rate (5°C/min). The two groups of samples show different growth kinetics for Goss grains, in which at the longest annealing time, the rapid heating sample exhibits larger maximum Goss grain size compared to the slower heated samples.

Non-Isothermal Austenite Grain Growth Kinetics in the HAZ of a Microalloyed X-80 Linepipe Steel

2011 ◽  
Vol 172-174 ◽  
pp. 809-814 ◽  
Author(s):  
Kumkum Banerjee ◽  
Michel Perez ◽  
Matthias Militzer
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Electron Microscopic ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Grain Growth Kinetics ◽  
Austenite Grain Growth ◽  
Linepipe Steel

Non-isothermal austenite grain growth kinetics under the influence of several combinations of Nb, Ti and Mo containing complex precipitates has been studied in a microalloyed linepipe steel. The goal of these studies is the development of a grain growth model to predict the austenite grain size in the weld heat affected zone (HAZ). A detailed electron microscopic investigations of the as-received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. Inter and intragranular precipitates of ~5-150 nm have been observed. The steel has been subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350°C at various heating rates of 10, 100 and 1000°C/s. Thermal cycles have been found to have a strong effect on the final austenite grain size. The increase in heating rate from 100 to 1000°C/s has a negligible difference in the austenite grain size irrespective of the austenitizing temperature. However, the increase in grain size has been noticed at 10°C/s heating rate for all the austenitizing temperatures. The austenite grain growth kinetics have been explained taking into account the austenite growth in the presence of precipitates.

Austenite Grain Growth Kinetics during Continuous Heating of a Microalloyed X-80 Linepipe Steel

2012 ◽  
Vol 715-716 ◽  
pp. 292-296
Author(s):  
Kumkum Banerjee ◽  
Michel Perez ◽  
Matthias Militzer
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Continuous Heating ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Grain Growth Kinetics ◽  
Austenite Grain Growth ◽  
Linepipe Steel

Non-isothermal austenite grain growth kinetics has been studied in a microalloyed linepipe steel with complex precipitates containing Ti, Nb and/or Mo. The goal of these experimental studies is to provide the basis for the development of a grain growth model to predict the austenite grain size evolution in the weld heat affected zone (HAZ). Detailed electron microscopic investigations of the as received steel proved the presence of Ti-rich, Nb-rich and Mo-rich precipitates. The steel was subjected to austenitizing heat treatments to selected peak temperatures of 950, 1150 and 1350 °C at heating rates of 10, 100 and 1000 °C/s, respectively. Thermal cycles have been found to have a strong effect on the austenite grain size. Austenite grain sizes increase with peak temperature and decreasing heating rate. However, the increase in heating rate from 100 to 1000 °C/s has a negligible effect on the austenite grain size. The observed austenite grain growth kinetics can be explained taking into account the potential dissolution of Nb-rich precipitates.

Effect of Annealing on Magnetic Properties and Domain Structures of FePt Thin Films by Rapid Thermal Annealing Technique

2009 ◽  
Vol 79-82 ◽  
pp. 911-914
Author(s):  
S.C. Chen ◽  
T.H. Sun ◽  
Po Cheng Kuo
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Heating Rate ◽  
Domain Structure ◽  
Rapid Thermal Annealing ◽  
Annealing Time ◽  
Annealing Temperature ◽  
High Heating Rate ◽  
Fept Film ◽  
High Heating

Single-layered FePt films of 30 nm thick were annealed at temperature between 300 and 800 °C for 1–180 sec by a rapid thermal annealing (RTA) with a high heating rate of 100 °C/sec. It is found that both the grain size and magnetic domain size of the FePt film increase with increasing annealing temperature and annealing time. The FePt films exhibited soft magnetic properties and without domain images were observed by magnetic force microscope (MFM) when the films were post-annealed at below 500 °C for 180 sec. The in-plane coercivity (Hc//) and perpendicular coercivity (Hc⊥) of FePt film increases significantly to 7.5 and 6.5 kOe respectively as annealing temperature increases to 600 °C. When the annealing temperature is increased to 700 °C, they are increased to 11.1 and 9.5 kOe, respectively, and the domain structure inclines to isolated domain. However, further increasing the annealing temperature to 800 °C, the Hc// and Hc⊥ values decrease to 9.8 and 8.9 kOe respectively due to largely increase the grain size of FePt and change the domain structure from isolation to continuity. On the other hand, in order to transform the FePt film from disordered γ phase to the ordered L10 phase, the annealing time of over 3 seconds is necessary when the film was post-annealed at 700 °C with a high heating rate of 100 °C/sec by RTA technique.

Effect of Tensile Deformation on the Grain Size of Annealed Grain Non-Oriented Electrical Steel

2009 ◽  
Vol 1243 ◽  
Author(s):  
J. Salinas B. ◽  
A. Salinas
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Annealing Temperature ◽  
Electrical Steel ◽  
Tensile Deformation ◽  
Strain Range ◽  
Final Annealing ◽  
Steel Sheets ◽  
Recrystallized Grain Size ◽  
Type Of Behavior

ABSTRACTAn experimental study on the effect of tensile deformation on recrystallized grain size has been carried out in order to establishing the optimal deformation needed to accelerate grain growth during final annealing of semi-processed non-oriented Si-Al, low C electrical steel sheets. The material is deformed in tension to strains from 3 to 20% and then air-annealed at temperatures between 700 and 900 °C. The results show that the critical deformation for recrystallization (8%) is independent of annealing temperature. However, the critical recrystallized grain size increases with annealing temperature from 160 to 240 μm. After that, the grain size decreases exponentially with increasing deformation. Abnormal grain growth is observed in samples annealed at 700 °C after strains in the range from 7 to 12%. This type of behavior is also observed in specimens annealed at 800 and 900 °C, however, in this case the pre-strain range is expanded to 3–12%. Normal grain growth is observed in samples pre-deformed to strains larger than 12%. In this case, the final grain size after 2 hour anneal is about 55 μm, also independent of annealing temperature. The possible implications of these results on the magnetic properties of these materials are discussed.

Microwave sintering of ZnO at ultra high heating rates

2001 ◽  
Vol 16 (10) ◽  
pp. 2850-2858 ◽  
Author(s):  
Geng-fu Xu ◽  
Isabel K. Lloyd ◽  
Yuval Carmel ◽  
Tayo Olorunyolemi ◽  
Otto C. Wilson
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Microwave Heating ◽  
Grain Growth ◽  
Rapid Heating ◽  
Microwave Sintering ◽  
Complete Suppression ◽  
Heating Rates ◽  
High Heating ◽  
Size Uniformity

In this paper, a unique processing approach for producing a tailored, externally controlled microstructure in zinc oxide using very high heating rates (to 4900 °C/min) in a microwave environment is discussed. Detailed data on the densification, grain growth, and grain size uniformity as a function of heating rate are presented. With increasing heating rate, the grain size decreased while grain size uniformity increased. At extremely high heating rates, high density can be achieved with almost complete suppression of grain growth. Ultrarapid microwave heating of ZnO also enhanced densification rates by up to 4 orders of magnitude compared to slow microwave heating. The results indicate that the densification mechanisms are different for slow and rapid heating rates. Since the mechanical, thermal, dielectric, and optical properties of ceramics depend on microstructure, ultrarapid heating may lead to advanced ceramics with tailored microstructure and enhanced properties.

STRUCTURAL CHARACTERISTICS OF (Ba,Sr)TiO3 THIN FILMS BY RAPID THERMAL ANNEALING

2007 ◽  
Vol 14 (01) ◽  
pp. 141-145
Author(s):  
Q. Y. ZHANG ◽  
S. W. JIANG ◽  
Y. R. LI
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Heating Rate ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Rapid Heating ◽  
Structural Characteristics ◽  
High Heating Rate ◽  
Duration Time ◽  
Temperature Heating

The rapid thermal annealing (RTA) process was adapted to crystallize the amorphous ( Ba,Sr ) TiO 3 thin films prepared on Si (111) substrates by RF magnetic sputtering deposition. The effect of annealing temperature, heating rate and duration time on crystallization was studied through X-ray diffraction and atomic force microscopy. The result shows that the crystallinity and grain size were strongly dependent on the temperature, heating rate, and duration time. Higher heating rate leads to smaller grain size. In high heating rate, the grain size shows different dependence of temperature from that of low heating rate. For a heating rate of 50°C/s, the grain size decreased with temperature increasing below 700°C, while after that temperature, the grain size increased slightly with the temperature increasing. At a certain temperature, the crystallinity and surface roughness improved with increase in annealing time, while grain size changed little. The effect of rapid heating rate on the nucleation and grain growth has been discussed, which contributes to the limited grain size of the annealed ( Ba,Sr ) TiO 3 thin films.

The Influence of Grain Size Determination Method on Grain Growth Kinetics Analysis

2015 ◽  
Vol 17 (11) ◽  
pp. 1598-1607 ◽  
Author(s):  
Leyla Hashemi-Sadraei ◽  
S. Ebrahim Mousavi ◽  
Enrique J. Lavernia ◽  
Julie M. Schoenung
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Size Determination ◽  
Determination Method ◽  
Kinetics Analysis ◽  
Grain Growth Kinetics

scholarly journals The Effect of Ultra-Fast Heating on the Microstructure, Grain Size and Texture Evolution of a Commercial Low-C, Medium-Mn DP Steel

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 877 ◽  
Author(s):  
Alexandros Banis ◽  
Eliseo Hernandez Duran ◽  
Vitaliy Bliznuk ◽  
Ilchat Sabirov ◽  
Roumen H. Petrov ◽  
...  
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Rapid Heating ◽  
Texture Evolution ◽  
Heating Time ◽  
Manganese Steel ◽  
Low Carbon ◽  
Fast Heating ◽  
Suitable Alternative ◽  
Heated Sample

The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over the last year as it imposes a suitable alternative for the production of ultra high strength steel grades. Rapid reheating followed by quenching leads to fine-grained mixed microstructures. This way the desirable strength/ductility ratio can be achieved while the use of costly alloying elements is significantly reduced. The current work focuses on the effect of ultra-fast heating on commercial dual phase grades for use in the automotive industry. Here, a cold-rolled, low-carbon, medium-manganese steel was treated with a rapid heating rate of 780 °C/s to an intercritical peak temperature (760 °C), followed by subsequent quenching. For comparison, a conventionally heated sample was studied with a heating rate of 10 °C/s. The initial microstructure of both sets of samples consisted of ferrite, pearlite and martensite. It is found that the very short heating time impedes the dissolution of cementite and leads to an interface-controlled α → γ transformation. The undissolved cementite affects the grain size of the parent austenite grains and of the microstructural constituents after quenching. The final microstructure consists of ferrite and martensite in a 4/1 ratio, undissolved cementite and traces of austenite while the presence of bainite is possible. Finally, it is shown that the texture is not strongly affected during ultra-fast heating, and the recovery and recrystallization of ferrite are taking place simultaneously with the α → γ transformation.

Zum Kornwachstum beim reinen und dotierten polykristallinen Selen / Grain Growth of Pure and Doped Poly crystalline Selenium

1971 ◽  
Vol 26 (7) ◽  
pp. 1198-1201
Author(s):  
C. Weyrich
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
Grain Growth ◽  
Annealing Time ◽  
High Purity ◽  
The Mean ◽  
Grain Surface ◽  
Polycrystalline Form ◽  
Grain Diameter

Abstract Grain Growth of Pure and Doped Poly crystalline Selenium Samples of vitreous high-purity selenium as well as vitreous chlorine-and thallium-doped selenium have been brought into the polycrystalline form by annealing. The dependence of grain size on annealing time tu was measured. In high-purity selenium and in chlorine-doped selenium the mean grain diameter increases essentially ~ tu1/2 , in thallium-doped selenium ~ tu1/2 , as is expected from the laws of grain growth. The proportionality between electrical conductivity and specific grain surface reported by other authors could not be verified.

Cu2S and AlN Precipitates in Fe-3%Si-0.5%Cu Steel Produced by Low Slab Reheating Technique

2013 ◽  
Vol 790 ◽  
pp. 69-72 ◽  
Author(s):  
Yang Wang ◽  
Yun Bo Xu ◽  
Yuan Xiang Zhang ◽  
Feng Fang ◽  
Xiang Lu ◽  
...  
Keyword(s):  
Grain Growth ◽  
Hot Rolling ◽  
Secondary Recrystallization ◽  
Primary Recrystallization ◽  
Silicon Steel ◽  
Recrystallization Annealing ◽  
Mean Size ◽  
The Mean

The grain oriented silicon steel containing 3%Si-0.5%Cu was produced by low slab reheating temperature technique. The precipitates were observed during the mainly process such as hot rolling, normalization, primary and secondary recrystallization annealing. The species, size, density and shape of precipitates were identified using TEM technique. The results indicate that Cu2S and AlN are mainly inhibitors which precipitate during hot rolling and normalization respectively. After primary recrystallization annealing the precipitation size of Cu2S is in the range of 30~40nm while the mean size of AlN is ~50nm, which could inhibit grain growth. In addition, the precipitation of MnS is inhibited comparing with the precipitation of Cu2S.

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