Texture Change during Grain Growth in Non-Oriented Electrical Steel

2013 ◽  
Vol 753 ◽  
pp. 329-332
Author(s):  
Yoshihiro Arita ◽  
Yoshiyuki Ushigami ◽  
Kenichi Murakami ◽  
Kohsaku Ushioda
Keyword(s):  
Grain Growth ◽  
Electrical Steel ◽  
Abnormal Grain Growth ◽  
Initial Structure ◽  
Rolled Steel ◽  
Ebsd Data ◽  
Texture Change ◽  
Average Grain Size ◽  
Cold Rolled ◽  
Initial Texture

Texture change during grain growth in Fe-3%Si non-oriented electrical steel was investigated. Cold rolled steel, 0.35mm in thickness, was annealed and recrystallized as an initial structure. Normal grain growth and abnormal grain growth occurred by additional annealing. {111} was dominant in the initial texture. However {100} component, which was not in majority in the initial structure, became stronger after normal grain growth. It was revealed that an average grain size of {100} in the initial structure was bigger than those of other components by analysis of the EBSD data,. Therefore, it is concluded that {100} strengthened after normal grain growth due to its size advantage. On the other hand, {111} components became more stronger after abnormal grain growth. It is inferred that another mechanism of the texture change worked in abnormal grain growth.

Effects of Cold Work on Abnormal Grain Growth During Simulated Carburizing of 4121 Steel Containing Nb

2021 ◽  
Author(s):  
Sukjin Lee ◽  
Eun Jung Seo ◽  
Robert L. Cryderman ◽  
David K. Matlock ◽  
John G. Speer
Keyword(s):  
Grain Growth ◽  
Cold Work ◽  
Abnormal Grain Growth ◽  
Reduction Ratio ◽  
Cold Forging ◽  
Cold Rolling Reduction ◽  
Martensitic Microstructure ◽  
Cold Rolled ◽  
Austenite Grain Growth ◽  
Nb Addition

Abstract Precision cold-forging processes are used to produce near-netshape parts that may then be carburized. During carburization thermal cycles, abnormal grain growth (AGG) after cold forging is known to develop microstructures which limit fatigue strength. In the present study, a small 0.04 wt.% Nb addition was made to a low-alloyed AISI 4121 steel containing 0.3 wt.% Mo. Subcritically annealed specimens were cold rolled (to simulate cold forging) at selected reduction ratios up to 50%, heated according to a simulated gas carburizing cycle at 930 °C, and water quenched to produce a final martensitic microstructure. The number density of abnormally grown grains increased rapidly as the cold rolling reduction ratio increased from 0 to 10%. With a further increase in reduction ratio, the extent of AGG decreased and was absent in samples subjected to the maximum reduction ratio of 50%. The evolution of fine (Nb, Mo)(C,N) precipitates at various stages of processing was characterized by thermodynamic calculations and electron microscopy and compared to the occurrence of abnormal austenite grain growth. The significance of these results for controlling AGG and thus optimizing fatigue performance in commercially-produced cold-forged and carburized components is discussed.

Crystallographic texture change during abnormal grain growth in Cu‐Co thin films

1994 ◽  
Vol 65 (2) ◽  
pp. 177-179 ◽  
Author(s):  
J. M. E. Harper ◽  
J. Gupta ◽  
D. A. Smith ◽  
J. W. Chang ◽  
K. L. Holloway ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Growth ◽  
Crystallographic Texture ◽  
Abnormal Grain Growth ◽  
Texture Change

Magnetic Annealing on GNO Electrical Steel Fe-3.25% Si

2013 ◽  
Vol 758 ◽  
pp. 113-117 ◽  
Author(s):  
Gilberto Alexandre Castello-Branco ◽  
Jennifer Nadine Muller ◽  
Cristiane Maria Basto Bacaltchuk
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Electrical Steel ◽  
Annealing Process ◽  
Magnetic Annealing ◽  
Average Grain Size ◽  
Orientation Density ◽  
Cold Rolled ◽  
Small Grains ◽  
Electrical Motors

Grain non-oriented electrical steel has its main application in electrical motors and its microstructure significantly influences their efficiency. The objective of this work was to investigate whether or not magnetic field applied during annealing process affects grain growth and the development of important texture components leading to an improvement of the magnetic properties. GNO Fe-3.25%Si 75% cold rolled specimens were annealed inside magnetic field with strength of 17 T at the temperature of 800°C for 3, 10 and 30 minutes. Results of average grain size after magnetic annealing showed a microstructure formed by small grains and a few very large grains. Magnetic field did not increase orientation density of {100} oriented grains and Goss grains but was able to increase density of θ fiber and decrease the density of γ fiber.

Kinetics of columnar abnormal grain growth in low-Si non-oriented electrical steel

2004 ◽  
Vol 385 (1-2) ◽  
pp. 449-454 ◽  
Author(s):  
Mykola Džubinský ◽  
Yuriy Sidor ◽  
František Kováč
Keyword(s):  
Grain Growth ◽  
Electrical Steel ◽  
Abnormal Grain Growth ◽  
Kinetics Of

Nucleation and Abnormal Grain Growth of Alpha-A12O3 in Gamma-Alumina Matrix

1991 ◽  
Vol 230 ◽  
Author(s):  
T. C. Chou ◽  
T. G. Nieh
Keyword(s):  
Grain Growth ◽  
Boundary Migration ◽  
Abnormal Grain Growth ◽  
Alumina Matrix ◽  
Orientation Relationships ◽  
Nucleation Kinetics ◽  
Alumina Films ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Sputter Deposited

AbstractThe microstructures of reactive sputter-deposited alumina films have been studied by transmission electron microscopy. The as-deposited films contained γ-A12O3 phase in an amorphous alumina matrix. Annealing of the films at 1200° C for 2 h resulted in nucleation and concurrent anomalous grain growth of α-A12O3 in a polycrystaUine γ-Al2O3 matrix which exhibited a layered microstructure and was strongly textured along [001]. The grain sizes of α-A12O3 varied from 3 to 20 μm, while the average grain size of γ-A12O3 was only about 50 nm. It appears that the nucleation kinetics of a-A12O3 was slow. As a result, the abnormal grain growth of α-A12O3 proceeded by consuming surrounding γ-Al2O3 grains. An atomic model is presented to explain the origin of layered structure in γ-A12O3. The nucleation mechanism of a-A12O3 in γ-alumina matrix is suggested. Orientation relationships between γ- and α-A12O3 are reported. The anomalous grain growth of α- A12O3 is discussed in terms of γ/α interface boundary migration.

scholarly journals Mechanistic Approach of Goss Abnormal Grain Growth in Electrical Steel: Theory and Argument

2019 ◽  
Author(s):  
Soran Birosca ◽  
Ali Nadoum ◽  
Diween Hawezy ◽  
Fiona Robinson ◽  
Winfried Kockelmann
Keyword(s):  
Grain Growth ◽  
Electrical Steel ◽  
Abnormal Grain Growth ◽  
Mechanistic Approach

In Situ Observation of Grain Growth and Recrystallization of Steel at High Temperature

2010 ◽  
Vol 638-642 ◽  
pp. 1077-1082 ◽  
Author(s):  
Yasuhiro Yogo ◽  
Kouji Tanaka ◽  
Koukichi Nakanishi
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Grain Growth ◽  
In Situ Observation ◽  
Initial Structure ◽  
Grain Sizes ◽  
Dynamic Observation ◽  
Average Grain Size ◽  
Observation Method

An in-situ observation method for structures at high temperature is developed. The new observation device can reveal grain boundaries at high temperature and enables dynamic observation of these boundaries. Grain growth while maintaining microstructure at high temperature is observed by the new observation device with only one specimen for the entire observation, and grain sizes are quantified. The quantifying process reveals two advantages particular to the use of the new observation device: (1) the ability to quantify grain sizes of specified sizes and (2) the results of average grain size for many grains have significantly less errors because the initial structure is the same for the entire observation and the quantifying process. The new observation device has the function to deform a specimen while observing structures at high temperature, so that enables it to observe dynamic recrystallization of steel. The possibility to observe recrystallization is also shown.

Abnormal Grain Growth on the Surface of Cold-Rolled AA1235 Aluminum Plate during the Annealing Process

2017 ◽  
Vol 898 ◽  
pp. 1123-1133
Author(s):  
Y.Z. Zhu ◽  
Xiao Hui Li ◽  
J.C. Li ◽  
Wei Long Fan ◽  
Cheng Wei Xia ◽  
...  
Keyword(s):  
Grain Growth ◽  
Orientation Angle ◽  
Abnormal Grain Growth ◽  
Bottom Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Abnormal Growth ◽  
Cold Rolled ◽  
Twin Roll Cast ◽  
Twin Roll

AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} <001> texture was formed in the surrounding normal grains adjacent to the abnormal grain. The orientation angle between the abnormal grain and its adjacent normal grains was 45°. The {100} <001> texture formed during rolling and annealing accelerated abnormal grain growth. The partially dissolved Fe precipitates were heterogeneously distributed in the plate bottom heterogeneously, which also mainly explained abnormal grain growth.

Influence of Heating Rate and Decarburization Temperature on the Microstructure and Magnetic Properties of Grain Oriented Electrical Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2622-2627 ◽  
Author(s):  
Chun Kan Hou ◽  
Jian Ming Tzeng
Keyword(s):  
Magnetic Properties ◽  
Heating Rate ◽  
Grain Growth ◽  
Electrical Steel ◽  
Rapid Heating ◽  
Abnormal Grain Growth ◽  
Heating Rates ◽  
Abnormal Growth ◽  
Steel Sheets ◽  
Microstructure And Magnetic Properties

Effects of three heating rates, 5, 20/min., and 300°C/sec and decarburization temperature, 700-850°C in primary annealing on the microstructure and magnetic properties of a grain oriented electrical steel were investigated. It was found that the oxide layer thickness and grain size increased with increasing decarburization temperature. However, they decreased with increasing heating rate. On the other hand, injection nitrogen content into steel sheets decreased with increasing decarburization temperature. The percentage of abnormal grain growth obtained a peak value at 800°C in the specimens treated with heating rate less than 20°C per minute. But specimens with rapid heating rate, percentage of abnormal grain growth increased with increasing decarburization temperature. As percentage of abnormal growth increased, magnetic properties got better.

Sign in / Sign up

Export Citation Format

Share Document