scholarly journals The effect of Nb content on precipitates, microstructure and texture of grain oriented silicon steel

2019 ◽  
Vol 38 (2019) ◽  
pp. 628-638 ◽  
Author(s):  
Yong Wang ◽  
Chengyi Zhu ◽  
Guangqiang Li ◽  
Yu Liu ◽  
Bowen Zhou
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Hot Rolling ◽  
Silicon Steel ◽  
Pinning Force ◽  
Number Density ◽  
Goss Texture ◽  
Treatment Processes ◽  
Nb Content ◽  
Evolution Of Precipitates

AbstractNiobium has the potential as an inhibitor forming element in grain oriented silicon steel. The grain oriented silicon steels with different Nb contents (0.028 wt% and 0.052 wt%) were prepared, and the effect of Nb content on the evolution of precipitates, microstructure and texture were investigated by the various analysis methods and thermodynamic calculations. The results show that the smaller size and larger number density of precipitates were obtained in the sample with low Nb steel after hot rolling. In the process of normalization, Nb(C, N) are more inclined to precipitate along the dislocations caused by hot rolling, contributing to finer and more dispersed precipitates in normalized bands. The finer and more dispersed precipitates in 0.028% Nb containing silicon steel perform a stronger pinning force during whole heat treatment processes, resulting in the smaller grain size and higher intensity of Goss texture in the specimen containing 0.028%Nb. After normalization, the intensities of Goss texture in both steels decrease.

The Method of Eliminating Banded Structure and the Effects of Banded Structure on the Transverse Properties in 20G Steel

2013 ◽  
Vol 347-350 ◽  
pp. 1171-1175 ◽  
Author(s):  
Bin Wang ◽  
Hong Mei Hu ◽  
Cui Zhou
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Stress Concentration ◽  
Base Metal ◽  
Metallic Inclusion ◽  
Banded Structure ◽  
Grain Sizes ◽  
Fine Grain ◽  
Treatment Processes ◽  
Metallic Inclusions

The transverse properties were inferior to the longitudinal properties for the existence of banded structure in 20G steel. In order to eliminate the banded structure and improve the transverse performance of 20G steel, different heat treatment processes were adopted. The results showed that conventional normalizing could reduce the banded structure and refine the grain sizes. When 20G was heated with 10°C/min heating rated and then held at 920°C for 2h, the banded structure in the steel was almost eliminated and the microstructure was homogeneous with fine grain size, the strength increased by 14%. The non-metallic inclusion and carbide in the microstructure leaded to stress concentration and separation with the base metal. To some extent, heat treatment can improve the distribution and form of non-metallic inclusions.

Researches on Microstructures and Mechanical Properties of Extruded Mg-Zn-Zr-Y Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 715-717
Author(s):  
Jian Peng ◽  
Rong Shen Liu ◽  
Ding Fei Zhang ◽  
Cheng Meng Song
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Aging Treatment ◽  
High Strength ◽  
Treatment Processes ◽  
Medium Strength ◽  
Microstructures And Mechanical Properties ◽  
Extruded Products

The microstructures and mechanical properties of Mg-Zn-Zr-Y alloy extruded bar with different heat treatment processes were investigated, including solution treatments of 400 oC, 450 oC and 500 oC for 3 hours followed by 170 oC×24h aging treatment, and solely aging treatments of 160 oC, 180 oC for 24hours without solution after extruding. By comparing the grain size, strength and elongation of the samples, the heat treatment processes for extruded products with high strength and with medium strength were recommended.

Orientation Selectivity of Secondary Recrystallization in Grain-Oriented Silicon Steel

2013 ◽  
Vol 753 ◽  
pp. 337-340 ◽  
Author(s):  
Yoshiyuki Ushigami ◽  
Yoshihiro Arita ◽  
Kohsaku Ushioda
Keyword(s):  
Grain Size ◽  
Boundary Energy ◽  
Secondary Recrystallization ◽  
Silicon Steel ◽  
Orientation Selectivity ◽  
Pinning Force ◽  
Grain Boundary Energy ◽  
Deviation Angle ◽  
The Matrix ◽  
Goss Orientation

It has been observed that grain size of Goss secondary grain has a strong correlation with deviation angle from the exact Goss orientation and sharper Goss grain has larger grain diameter. This orientation selectivity of secondary recrystallization has been investigated with the statistical model of grain growth in which inhibitor and texture are taken into account. The model assumes that sharper Goss grain has a higher frequency of CSL boundaries to the matrix grains and thus has lower statistical grain boundary energy and suffers lower pinning force from the inhibitor. The analysis showed that this model successfully explains orientation selectivity and depicts the effect of inhibitor and texture.

Microstructure, Texture and Inhibitors of the As-Cast and Hot Rolled Grain-Oriented Silicon Steel by Strip Casting

2016 ◽  
Vol 852 ◽  
pp. 101-104 ◽  
Author(s):  
Wen Qiang Liu ◽  
Cheng Shuai Lei ◽  
Han Mei Tang ◽  
Hong Yu Song ◽  
Hai Tao Liu
Keyword(s):  
Hot Rolling ◽  
Texture Evolution ◽  
Fiber Texture ◽  
Silicon Steel ◽  
Rolling Reduction ◽  
Recrystallization Annealing ◽  
Goss Texture ◽  
Steel Strips ◽  
Columnar Grains ◽  
Hot Rolled

The microstructure and texture evolution of the as-cast and hot rolled grain-oriented silicon steel strips was investigated, and the precipitation of the inhibitors of the hot rolled strips was clarified. The results showed that the microstructure of the as-cast strip was characterized by coarse columnar grains with strong {001}<0vw> fiber texture. The microstructure of hot rolled strips was composed of ferrite and pearlite and the microstructure was gradually refined with increasing hot rolling reduction. In the hot rolled strips, α and γ fiber textures were enhanced at the expense of initial {001}<0vw> fiber texture and Goss texture was generated in the surface and sub-surface layer with increasing hot rolling reduction. Besides, a great number of dispersed MnS particles with the size of 20-30nm were observed in the hot rolled strips. These MnS particles could act as the effective inhibitors during the second recrystallization annealing of the grain-oriented silicon steel.

Microstructure and texture evolution of medium temperature grain-oriented silicon steel produced by industrialization

2019 ◽  
Vol 116 (6) ◽  
pp. 604 ◽  
Author(s):  
Lifeng Fan ◽  
Liying Jia ◽  
Rong Zhu ◽  
Jianzhong He
Keyword(s):  
Grain Size ◽  
Texture Evolution ◽  
Silicon Steel ◽  
Rolled Strip ◽  
Medium Temperature ◽  
Goss Texture ◽  
Hot Rolled Strip ◽  
Average Grain Size ◽  
Average Size ◽  
Hot Rolled

The grain-oriented silicon steel was produced by medium temperature reheating and two-stage cold rolling process, and the microstructure and texture of all metallurgical processes were studied. The results shown that the microstructure of the hot rolled strip was inhomogeneous in thickness direction, the surface layer was the recrystallized microstructures with average grain size of 42.29 µm, the center layer was fiber structure, and the Goss texture appeared at surface. The primary recrystallized microstructure with average grain size of 16 µm was obtained after decarburization annealing, which characterized by a strong γ-fiber texture and a weak Goss texture. The average size of inhibitors in hot rolled strip and decarburization annealed sheet were 9.078 and 21.691 nm respectively, they were mainly compound of nitride and sulfide with spherical or lump shapes. The coarse Goss grains with average size 17.57 mm were got after secondary recrystallization, and the magnetic induction B8 and iron loss P1.7/50 were 1.885 T and 1.10 W/Kg, respectively.

Secondary Recrystallization in Grain-Oriented Silicon Steel

2004 ◽  
Vol 467-470 ◽  
pp. 853-862 ◽  
Author(s):  
Yoshiyuki Ushigami ◽  
Tomoji Kumano ◽  
Tsutomu Haratani ◽  
Shuichi Nakamura ◽  
Shigeto Takebayashi ◽  
...  
Keyword(s):  
Boundary Energy ◽  
Secondary Recrystallization ◽  
Silicon Steel ◽  
Second Phase ◽  
In Situ Observation ◽  
Pinning Force ◽  
Goss Texture ◽  
Second Phase Particles ◽  
The Matrix ◽  
Grain Growth Behavior

Mechanism of Goss secondary recrystallization in grain-oriented silicon steel has been investigated by temperature gradient annealing and by in situ observation utilizing synchrotron x-ray topography. The results support the selective growth theory. Migration of Goss grains is controlled by second phase particles (inhibitor) and sharper Goss grains, which have higher frequency of CSL boundaries to the matrix, start to grow preferentially while the other matrix grains are stagnated by inhibitor. CSL boundaries are supposed to have lower grain boundary energy, thus suffer lower pinning force from the inhibitor and start to migrate at higher inhibition level. Based on this model, we have made a computer simulation and have found that this model successfully depicts the important features of secondary recrystallization; grain growth behavior of secondary grains, secondary grain size and sharpness of Goss texture.

The Influence of Hot Rolling Technological Parameters on Microstructure of Low Temperature Grain-Oriented Silicon Steel

2011 ◽  
Vol 396-398 ◽  
pp. 1841-1845
Author(s):  
Yun Li Feng ◽  
Xue Jing Qi ◽  
Meng Song
Keyword(s):  
Hot Rolling ◽  
Room Temperature ◽  
Secondary Recrystallization ◽  
Silicon Steel ◽  
Rolled Strip ◽  
Technological Parameters ◽  
Coiling Temperature ◽  
Goss Texture ◽  
Gleeble 3500 ◽  
Hot Rolled

The process of hot rolling Fe-3.15% Si steel is simulated by Gleeble-3500 thermal mechanical simulator, the influence of finishing temperature, coiling temperature and cooling rates after rolling on microstructure of Fe-3.15% Si steel are mainly researched, and the influence of hot rolled microstructure on Goss texture, secondary recrystallization and magnetic property are analysed. The results show that the nonuniform microstructures of hot rolled strip play an important role in developing the perfect secondary recrystallization. Fe-3.15% Si steel is rough rolled at 1110°C, finished rolled at 880°C, subsequently cooled to 550°C for coiling at rate of 10°C/s, then air cooled to room temperature. The above mentioned process could produce hot-rolled microstructure which are benefit to formation of Goss texture and the development of perfect secondary recrystallization.

scholarly journals Influence of Nb Content on Precipitation, Grain Microstructure, Texture and Magnetic Properties of Grain-Oriented Silicon Steel

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5581
Author(s):  
Yong Wang ◽  
Chengyi Zhu ◽  
Guangqiang Li ◽  
Yulong Liu ◽  
Yu Liu
Keyword(s):  
Magnetic Properties ◽  
Volume Fraction ◽  
Silicon Steel ◽  
Pinning Force ◽  
Final Annealing ◽  
Large Volume Fraction ◽  
Nb Content ◽  
Strong Pinning ◽  
Nb Addition ◽  
Precipitation Microstructure

The effects of Nb content on precipitation, microstructure, texture and magnetic properties of primary recrystallized grain-oriented silicon steel were investigated by various methods. The results show that the precipitates in primary recrystallized sheets are mainly MnS, Nb(C,N), composite precipitates of MnS and AlN, and composite precipitates of Nb(C,N) and AlN. Adding niobium could refine the primary recrystallized microstructure. The steel with 0.009 wt% Nb possesses the finest and the most dispersed precipitates, which contributes to the finest primary recrystallized microstructure due to the strong pinning force. Adding niobium is beneficial to obtain large volume fraction favorable texture for grain-oriented silicon steel, and the effect of Nb addition is not obvious when the content is higher than 0.009 wt%. After final annealing, the steel with 0.009 wt% Nb shows the best magnetic properties, B800 = 1.872 T, P1.7/50 = 1.25 W/kg.

Effect of Phase Composition and Microstructure of Oxide Scale on the Corrosion Resistance of SS400 Hot Rolled Strip

2011 ◽  
Vol 399-401 ◽  
pp. 1951-1957
Author(s):  
Xian Liang Zhou ◽  
Min Zhu ◽  
Xiao Zhen Hua ◽  
Zhi Guo Ye ◽  
Xia Cui ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Oxide Scale ◽  
Electrochemical Impedance ◽  
Rolled Strip ◽  
Fine Grain ◽  
Treatment Processes ◽  
The Difference ◽  
Hot Rolled

Different phase compositions and microstructures of oxide scales were formed on the surface of SS400 hot rolled alloys by employing various heat treatment processes. Cyclic wet-dry immersion corrosion test, electrochemical impedance spectroscopy were used to investigate the corrosion resistance of strips with scales fabricated by different heat treatment processes. The results reveal that difference in the corrosion resistance of the various scales is due to the difference in the grain size of Fe3O4phase. Furthermore, the difference in the corrosion resistance of different oxide phases, exhibited by various scales, also render the strips to give various corrosion behaviors. It is surmised that the strip with oxide scale, which consist of a small mount of the outer layer Fe2O3phase distributed continuously and a large quantity of the inner layer Fe3O4phase with the fine grain size, and possess nice compactness, continuity, integrity in the morphology structure, has the best corrosion resistance.

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