scholarly journals Effect of Annealing Prior to Cold Rolling on the Microstructure Evolution and Energy Losses of Low-Si, Ultra-Low-C Hot-Rolled Electrical Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 957
Author(s):  
Héctor Ortiz Rangel ◽  
Armando Salinas Rodríguez ◽  
Omar García Rincón
Keyword(s):  
Cold Rolling ◽  
Electrical Steel ◽  
Steel Strip ◽  
Rolling Direction ◽  
Annealing Treatment ◽  
Processing Parameters ◽  
Relative Effect ◽  
Strip Thickness ◽  
Energy Losses ◽  
Hot Rolled

The microstructure of a low Si, ultra-low-C, hot-rolled electrical steel strip is modified by annealing at T < To, the α→γ transformation temperature. This heat treatment causes the abnormal anisotropic growth of surface grains which consumes the original hot-rolled microstructure. The growth of the surface grains first takes place parallel to the rolling direction and then in a columnar form parallel to the normal direction until grains growing in opposite directions from the surfaces impinge at the center of the strip. It is shown that cold rolling and a short annealing treatment at temperatures between 700 and 800 °C leads to microstructures which result in iron energy losses that can be as much as 30% lower than those observed in the same material not subjected to the annealing prior to cold rolling. The magnitude of the reduction in energy losses depends on strip thickness and processing parameters. The major effect is observed in material annealed at 710 °C and the relative effect (with respect to material that is not annealed prior to cold rolling) decreases as the strip thickness decreases. It is shown that these effects can be attributed to the effect of the processing conditions on texture and grain size. The maximum reduction in energy losses is observed when the final microstructure consists of ferrite grains ~1.5 times larger than those obtained if the material is not annealed prior to cold rolling.

Effect of Hot-Rolled Microstructure on the Recrystallization Texture of Cold-Rolled Non-Oriented Electrical Steel

2011 ◽  
Vol 298 ◽  
pp. 203-208 ◽  
Author(s):  
Zi Li Jin ◽  
Wei Li ◽  
Yi Ming Li
Keyword(s):  
Cold Rolling ◽  
Electrical Steel ◽  
Texture Evolution ◽  
Steel Strip ◽  
Silicon Steel ◽  
Grain Structure ◽  
Recrystallization Annealing ◽  
Rolled Sheet ◽  
Cold Rolled ◽  
Hot Rolled

With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory，to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110}<UVW> texture components was enhanced and {100}<uwv> texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.

Processing and Microstructure of Grain Non-Oriented Electrical Steel Strips with Improved Magnetic Properties

2012 ◽  
Vol 706-709 ◽  
pp. 2800-2805 ◽  
Author(s):  
Armando Salinas-Rodríguez ◽  
E. Gutiérrez-Castañeda
Keyword(s):  
Magnetic Properties ◽  
Cold Rolling ◽  
Electrical Steel ◽  
Steel Strip ◽  
Annealing Treatment ◽  
Fiber Texture ◽  
Processing Route ◽  
Attractive Alternative ◽  
Final Annealing ◽  
Alternative Processing

The effects of annealing prior to cold rolling on the microstructure and magnetic properties of a low-C grain non-oriented (GNO) electrical steel strip have been investigated. It is shown that annealing of the hot-rolled strips in the intercritical region, Ac13, causes rapid decarburization and development of large columnar ferrite grains. This microstructure leads, after cold-rolling and a fast annealing treatment at temperatures between 800 and 850 °C, to a polygonal ferrite grain microstructure with magnetic properties superior to those observed typically in the same steel in the industrial fully processed condition. The results are attributed to the {100}-fiber texture developed during the final annealing. Annealing at T<800 °C or T>850 °C results in formation of {111}-fiber texture components due to recristallization or transformation of deformed ferrite leading to a negative effect on the final magnetic properties. The results suggest that annealing prior to cold rolling offers an attractive alternative processing route for the manufacture of fully processed low-C, Si-Al GNO electrical steels strips.

scholarly journals Influence of Hot Rolling Condition on the Final Microstructure of Non-Oriented Electrical Steel Fe-3.2 wt.% Si

2016 ◽  
Vol 854 ◽  
pp. 16-21 ◽  
Author(s):  
Anett Stöcker ◽  
Armin Franke ◽  
Harti Hermann ◽  
Rudolf Kawalla
Keyword(s):  
Cold Rolling ◽  
Hot Rolling ◽  
Electrical Steel ◽  
Final Thickness ◽  
Annealed Material ◽  
Cooling Conditions ◽  
Final Microstructure ◽  
Cold Rolling And Annealing ◽  
Cold Rolled ◽  
Hot Rolled

In this paper the microstructure evolution of an iron-silicon alloy with 3.2 wt.% silicon throughout the manufacturing stages hot rolling, cold rolling and annealing is presented. Starting with a 35 mm thick feedstock, which was hot rolled to 1 mm, with different cooling conditions, the material was cold rolled to a final thickness of 0.3 mm and final annealed under same conditions to show the influence of the hot rolling on the texture and microstructure of the final annealed material.

Edge drop and high spot control of hot-rolled non-oriented electrical steel strip by taper roll shifting strategy

2018 ◽  
Vol 47 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Chi-huan Yao ◽  
An-rui He ◽  
Jian Shao ◽  
Yun-jin Zhang ◽  
Hai-shan Zhao
Keyword(s):  
Electrical Steel ◽  
Steel Strip ◽  
Shifting Strategy ◽  
Hot Rolled ◽  
Edge Drop

Aptitude for Cold Rolling of Laser Welded Joints and their Environment in the Case of Steel Sheets

2010 ◽  
Vol 659 ◽  
pp. 127-133
Author(s):  
Gábor Buza ◽  
Dóra Janovszky ◽  
I. Zupkó ◽  
K. Tomolya ◽  
M. Sveda ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Welded Joint ◽  
Annealing Treatment ◽  
Hardness Profile ◽  
Ground Structure ◽  
Steel Sheets ◽  
Significant Difference ◽  
The Difference ◽  
Hot Rolled ◽  
Advantageous Effect

In order to perform a continuous cold rolling of steel sheets, hot rolled coils need to be attached to each other in order to get an endless sheet. This process can be achieved by laser key-hole welding as well. The structure and mechanical properties (e.g. hardness) of the welded joint without added metal, as well its heat affected zone differs significantly from the base metal. During our laboratory experiments the aptitude of cold rolling of joints and their environment, as well as the change in the features of materials was analyzed. During the rolling phases the hardness of the joint is higher than the ground structure, the strip thickness is modified depending on the difference of the hardness during the passes. According to our findings, the significant difference in measured hardness profile and texture structure prior to cold rolling and during cold rolling is minimized due to a recrystallisation annealing treatment following the cold rolling procedure. It is obvious that the normalization before cold rolling has advantageous effect to the properties of the welded joint. Elongation of the normalized samples is bigger than elongation of the non normalized samples.

Influence of Processing Parameters on the Texture Formation in Powder Metallurgic Ni-5at.%W Substrate Tapes

2007 ◽  
Vol 546-549 ◽  
pp. 1997-2002 ◽  
Author(s):  
Shao Kai Chen ◽  
C.F. Liu ◽  
Ping Xiang Zhang ◽  
Lian Zhou
Keyword(s):  
Cold Rolling ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Cube Texture ◽  
Annealing Treatment ◽  
Processing Parameters ◽  
Thickness Reduction ◽  
Texture Formation ◽  
Total Thickness ◽  
Electron Back Scattered Diffraction

Influence of cold rolling total thickness reduction, annealing temperature and annealing time on the textures in powder metallurgic Ni-5at.%W substrate tapes have been quantitatively investigated with the EBSD (Electron Back-Scattered Diffraction) technique. A “copper” type-like texture consisting of {1 2 3}<6 3 –4>+{0 1 –1}<3 –1 –1>+{1 –1 2}<1 –1 –1> has been found in the as-rolled tapes. This texture was much intensive in the tape at 99% thickness reduction than in the tape at 87% thickness reduction. The 99% reduction tape showed a higher fraction and sharper cube texture than the 87% reduction tape after annealing treatment. In addition, annealing at 1000°C was much favourable for the cube texture formation than annealing at 950°C and resulted in a higher cube texture fraction.

Magnetic Barkhausen Noise Characterization of the Recrystallization of a Non-Oriented Electrical Steel after Cold Rolling at Different Angles to the Hot Rolling Direction

2018 ◽  
Vol 941 ◽  
pp. 274-279
Author(s):  
You Liang He ◽  
Mehdi Mehdi ◽  
Erik J. Hilinski ◽  
Afsaneh Edrisy
Keyword(s):  
Magnetic Properties ◽  
Cold Rolling ◽  
Hot Rolling ◽  
Electrical Steel ◽  
Electron Backscatter Diffraction ◽  
Rolling Direction ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Final Annealing ◽  
Steel Sheets

Non-oriented electrical steel sheets are the most commonly used material for the manufacturing of magnetic cores for electric motors and generators. The microstructure and texture of the steel after final annealing have a significant effect on the magnetic properties of the lamination core. To investigate the effect of cold rolling and annealing on the magnetic properties of the steel sheets, a 0.9 wt% Si non-oriented electrical steel was cold rolled at different angles to the hot rolling direction (HRD) and annealed at various temperatures (600°C to 750°C) to produce dissimilar microstructures. The progress of recrystallization was characterized by electron backscatter diffraction (EBSD), and the magnetic response of the steel at various stages of recrystallization was evaluated by magnetic Barkhausen noise (MBN). A number of MBN parameters, e.g. the root mean square, the smoothed envelope, the peak, the full width at half maximum (FWHM) of the envelope, the time integral of the MBN signals and the MBN energy, were analyzed with respect to the fraction of recrystallization during annealing. The results show that cold rolling at different angles to the hot rolling direction induces various deformation microstructures and stored energies, which, in turn, lead to considerably different recrystallization behaviours during annealing. The difference in recrystallization of these materials is also reflected in the MBN parameters.

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