Effect of Coiling and Normalizing Annealing on the Microstructure of a Newly Developed Cold-Rolled Non-Oriented Electrical Steel

2013 ◽  
Vol 302 ◽  
pp. 298-303
Author(s):  
Yan Ping Zeng ◽  
Hui Jie Cui
Keyword(s):  
Grain Boundary ◽  
Electrical Steel ◽  
Volume Fraction ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Pinning Effect ◽  
Cold Rolled ◽  
Average Size ◽  
Hot Rolled ◽  
Normalizing Annealing

In order to improve the magnetic properties, copper was added to cold-rolled non-oriented electrical steel with low carbon and low silicon. The grain sizes and precipitates in hot-rolled bands of the investigated steel were quantitatively studied. The results show that the recrystallization of deformed grains has been completed in the coiled bands and the recrystallized grains are fine due to low coiling temperature and pinning effect of precipitates. But grains grew up obviously after normalizing annealing at 850°C for 1h because the mobility of grain boundary is so good at elevated temperature that pinning effect of precipitates can’t prevent the migration of grain boundary. Thus, normalizing annealing is necessary to obtain large grains in hot-rolled band. In addition, the typical morphologies of precipitates in hot-rolled bands are square, rectangular, hexagonal and triangular and they are identified as AlN phase based on EDS and SEAD analysis, which can form by epitaxial growth mode. For the hot-rolled bands coiled at 550°C, the increase of average size and volume fraction of AlN particles with coiling time is mainly related to the growth of AlN particles, whereas for the hot-rolled bands coiled at 650°C, the decrease of average size and the increase of volume fraction of AlN particles with coiling time are chiefly attributed to the precipitation of many small AlN particles. The volume fraction of AlN particles increases with coiling temperature because they precipitate more quickly at 650°C than at 550°C.

The Effect of Hot-Rolled Coiling Time on the Texture of a New Cold-Rolled Non-Oriented Electric Steel

2011 ◽  
Vol 194-196 ◽  
pp. 375-378
Author(s):  
Guan Qiao Hu ◽  
Yan Ping Zeng ◽  
Hai Lin Chen
Keyword(s):  
Hot Rolling ◽  
Electrical Steel ◽  
Volume Fraction ◽  
Test Results ◽  
Electric Steel ◽  
Coiling Temperature ◽  
Goss Texture ◽  
Cold Rolled ◽  
Hot Rolled

The effects of hot-rolling coiling time on texture of a new cold-rolled non-oriented electrical steel containing copper were investigated. The test results showed that the final product texture consists of γ-fibr textures, α-fibre textures and Goss. With adding coiling time ,the density of {111}<110> and {112}<110> decreased,the inverse Goss texture {001}<110> increased. The volume fraction of {100} raised with coiling time. As a certain coiling temperature, it can improve the intensity of textures {100},{110}at proper coiling time.

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.

scholarly journals Oriented Nucleation in Low-Carbon Steels

Texture ◽  
1974 ◽  
Vol 1 (3) ◽  
pp. 183-194 ◽  
Author(s):  
R. L. Every ◽  
M. Hatherly
Keyword(s):  
High Energy ◽  
Carbon Steels ◽  
Low Carbon ◽  
Line Broadening ◽  
Low Carbon Steels ◽  
X Ray ◽  
Cell Structures ◽  
Cold Rolled ◽  
Hot Rolled ◽  
Energy Components

The preferred orientations in hot-rolled, cold-rolled (70 % reduction), and annealed low-carbon steels (capped and aluminium-killed grades) have been investigated. Particular attention has been paid to the factors that control texture formation during annealing.The elastic energy stored in the cold-rolled steels is orientation dependent and the sequence, estimated from a Fourier analysis of X-ray line broadening, is V110>V111>V211>V100; the values range from 3.51 to 1.14 cal/g atom. The high energy components ({110}, {111}) have elongated cell structures but those of lower energy are equiaxed. In capped steels the high energy components recover and recrystallize most rapidly. In aluminium-killed steels both recovery and recrystallization are inhibited at low temperatures ≤ 500℃ and recrystallization begins first in the {111} components. It is shown that these effects are associated with precipitation and/or segregation of AlN during recovery. The recrystallization texture is determined primarily by oriented nucleation.

The Microstructure and Creep Behavior of Cold Rolled Udimet 188 Sheet

2010 ◽  
Vol 17 (3) ◽  
pp. 350-361
Author(s):  
C.J. Boehlert ◽  
S.C. Longanbach
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Creep Behavior ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Tensile Creep ◽  
Dislocation Creep ◽  
Grain Boundary Character Distribution ◽  
Air Cooling ◽  
Cold Rolled

AbstractUdimet 188 was subjected to thermomechanical processing (TMP) in an attempt to understand the effects of cold-rolling deformation on the microstructure and tensile-creep behavior. Commercially available sheet was cold rolled to varying amounts of deformation (between 5–35% reduction in sheet thickness) followed by a solution treatment at 1,464 K (1,191°C) for 1 h and subsequent air cooling. This sequence was repeated four times to induce a high-volume fraction of low-energy grain boundaries. The resultant microstructure was characterized using electron backscattered diffraction. The effect of the TMP treatment on the high-temperature [1,033–1,088 K (760–815°C)] creep behavior was evaluated. The measured creep stress exponents (6.0–6.8) suggested that dislocation creep was dominant at 1,033 K (760°C) for stresses ranging between 100–220 MPa. For stresses ranging between 25–100 MPa at 1,033 K (760°C), the stress exponents (2.3–2.8) suggested grain boundary sliding was dominant. A significant amount of grain boundary cracking was observed both on the surface and subsurface of deformed samples. To assess the mechanisms of crack nucleation, in situ scanning electron microscopy was performed during the elevated-temperature tensile-creep deformation. Cracking occurred preferentially along general high-angle grain boundaries (GHAB) and less than 25% of the cracks were found on low-angle grain boundaries (LAB) and coincident site lattice boundaries (CSLB). Creep rupture experiments were performed at T = 1,088 K (815°C) and σ = 165 MPa and the greatest average time-to-rupture was exhibited by the TMP sheet with the greatest fraction of LAB+CSLB. However, a clear correlation was not exhibited between the grain boundary character distribution and the minimum creep rates. The findings of this work suggest that although grain boundary engineering may be possible for this alloy, simply relating the fraction of grain boundary types to the creep resistance is not sufficient.

Development of Tensile Test to Investigate Mechanical Adhesion of Thermal Oxide Scales on Hot-Rolled Steel Strips Produced Using Different Finishing Temperatures

2011 ◽  
Vol 462-463 ◽  
pp. 407-412 ◽  
Author(s):  
Komsan Ngamkham ◽  
Satian Niltawach ◽  
Somrerk Chandra-ambhorn
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Ex Situ ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Steel Strips ◽  
Thermal Oxide ◽  
Mechanical Adhesion ◽  
Hot Rolled ◽  
Scale Surface

The objective of this work was to carry out tensile tests to investigate the effect of finishing temperature on mechanical adhesion of thermal oxide scale on hot-rolled low carbon steel strips. Two hot-rolled low carbon steel strips were produced in an industrial hot rolling line by fixing a coiling temperature at 620 °C and varying finishing temperatures at 820 and 910 °C. Two testing methods were conducted. First, each of a number of samples was subjected to a given imposed strain with ex-situ imaging of scale surface after straining. Second, only one sample was strained in a test with ex-situ imaging of scale surface at every 2 mm elongation of the sample. A spallation ratio, an area where scale was spalled out and normalised by the total area observed by microscope, was plotted as a function of the imposed strain. These two methods gave the same tendency of results as follows. At a given strain, the spallation ratio of scale on steel produced using higher finishing temperature was larger. The gradient of spallation ratio with respect to the imposed strain of that scale was also steeper. This reflects the higher susceptibility of scale to spall out with increasing imposed strain. This behaviour might be related to the larger thickness of scale on steel produced using higher finishing temperature. For the second testing method, lowering the magnification of microscope to observe scale spallation from 50x to 20x increased R2 of the curve of spallation ratio versus the imposed strain, as well as improved the reproducibility of the test.

Microstructures and Textures During Annealing in Low Carbon Al-Killed Steels with Low Finishing Temperatures and High Coiling Temperatures

2011 ◽  
Vol 194-196 ◽  
pp. 52-55 ◽  
Author(s):  
Bao Cai Wu ◽  
Feng Shi ◽  
Xin Yu Cheng ◽  
Rui Min Lin ◽  
Chun Ming Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Volume Fraction ◽  
Low Carbon ◽  
Coiling Temperature ◽  
X Ray ◽  
Obvious Advantage ◽  
Equiaxed Grain ◽  
Scanning Electron

Microstructures and textures after annealing at 680°C in low carbon Al-killed steels with low finishing temperature and high coiling temperature were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and X-Ray Diffractometer (XRD). The results show that higher coiling temperature and lower finishing temperature can both cause the appearance of equiaxed grain and line cementite. The equiaxed grain in 2# steel with higher coiling temperature is the more obvious. Advantage textures are weak in the steels with higher coiling temperature and lower finishing temperature and volume fraction of {111}fiber in 2# steel with higher coiling temperature is only 7.17%, so the stamping property should be worse.

Development of Hot Rolled Strips for Internal Plates of Automobile

2015 ◽  
Vol 817 ◽  
pp. 415-420
Author(s):  
Xing Dong Peng ◽  
Mei Ling Wang ◽  
Sheng Li Li ◽  
Jie Xu
Keyword(s):  
Hot Rolling ◽  
Aluminum Content ◽  
Manganese Content ◽  
Fatigue Properties ◽  
Steel Melting ◽  
Low Carbon ◽  
Slab Continuous Casting ◽  
Rolling Line ◽  
Cold Rolled ◽  
Hot Rolled

The hot rolled strips for internal plates of automobile was developed by taking the technologies of low-carbon softening steel, including strictly control the chemical composition content during the steel melting and optimization of the rolling processes in the thin slab continuous casting and rolling line. The results showed that when carbon content was 0.04%, adding aluminum content or reducing silicon content and manganese content, reducing the reduction in previous rolling passes and increasing the reduction of the finishing pass at high temperature was beneficial for reducing the yield strength and tensile strength of the hot rolled strips. The precipitate of the samples after annealing showed that the precipitate of aluminum-nitride increased significantly at 850°C. And the texture of the samples after annealing showed that the main texture was {110} <001> and its intensity was 1.7-2.0, annealing with hot rolled strips did not benefit the advantageous texture. Tension-tension fatigue properties of hot rolled strips and cold rolled ones were determined, the results showed that the fatigue properties of hot rolling strips were rather higher than that of cold rolled ones. In the stamping experiments of some automobile parts, there was not any drawback, and the forming properties of hot rolling strips were equal to that of cold rolled ones. It was feasible to replace the cold rolled strips with the hot rolled ones for the internal plates of automobile.

Effect of Cold Reduction Rate on Ferrite Recrystallization Behavior during Annealing in Low-Carbon Steel with Different Initial Microstructures

2021 ◽  
Vol 1016 ◽  
pp. 1045-1050
Author(s):  
Toshio Ogawa ◽  
Ryo Hishikawa ◽  
Yoshitaka Adachi
Keyword(s):  
Carbon Steel ◽  
Reduction Rate ◽  
Low Carbon Steel ◽  
Cold Reduction ◽  
Rolled Sheet ◽  
Recrystallization Behavior ◽  
Low Carbon ◽  
Dislocation Densities ◽  
Cold Rolled ◽  
Hot Rolled

We investigate the effect of the cold reduction rate on ferrite recrystallization behavior during the annealing of low-carbon steel with different initial microstructures. Three types of hot-rolled sheet specimens are prepared: specimens P, B, and M, which consist of ferrite and pearlite, bainite, and martensite, respectively. To evaluate the effect of the cold reduction rate on ferrite recrystallization behavior, hot-rolled sheet specimens are cold-rolled at cold reduction rates of 40% and 67%. The cold-rolled sheet specimens are heated to the target temperature, and then water-quenched to room temperature. Irrespective of the initial microstructures, the ferrite recrystallization is accelerated by increasing the cold reduction rate. In addition, the dislocation densities of specimens P and B increase at the larger cold reduction rate, which accelerates ferrite recrystallization in these specimens. In the case of specimen M, the dislocation arrangement parameter remarkably decreases at the larger cold reduction rate, whereas the dislocation density hardly changes. Thus, we conclude that the accelerated ferrite recrystallization at the larger cold reduction rate for specimen M can be mainly attributed to an increase in the amount of interactions between dislocations in the specimen.

Effect of Hot-Band Annealing on the Microstructure of Non-Oriented Electrical Steel Containing Copper

2012 ◽  
Vol 502 ◽  
pp. 238-242
Author(s):  
Di Nan ◽  
Yan Ping Zeng ◽  
Hui Jie Cui ◽  
Zi Yu Zhou
Keyword(s):  
Electrical Steel ◽  
Volume Fraction ◽  
Volume Fractions ◽  
Grain Sizes ◽  
Different Temperatures ◽  
Hot Band ◽  
Hot Rolled

The grain sizes and precipitates in hot-rolled bands of the non-oriented electrical steel containing Cu were quantitatively studied while the effect of hot-band annealing on microstructure was evaluated by hot-band annealing at different temperatures. The average sizes of recrystallized grains after coiling at 650°C are in the range of 24~29μm. After hot-band annealing at 850°C for 1h, grains coarsened dramatically. The volume fractions of precipitates in hot-rolled bands after coiling at 650°C for different time are 15~18%. After hot-band annealing, precipitates coarsened and distributed sparsely, and the volume fraction of them decreased to less than 10%.

Prediction of the Mechanical Properties of Hot-Rolled Low Carbon Steel Strips in Correlation to Chemical Compositions and Rolling Conditions

2011 ◽  
Vol 462-463 ◽  
pp. 401-406 ◽  
Author(s):  
Jiratthanakul Noppon ◽  
Somrerk Chandra-ambhorn
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Steel Strip ◽  
Low Carbon Steel ◽  
Chemical Compositions ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Empirical Formulas ◽  
The Difference ◽  
Hot Rolled

Seven thousand sets of data consisting of mechanical properties, chemical compositions, and rolling parameters of industrial hot-rolled coils were analysed using multiple regression. This was to establish empirical formulas to predict mechanical properties of steel as a function of chemical compositions and rolling parameters. The empirical formulas predicting yield strength (YS), ultimate tensile strength (UTS) and percentage of elongation (EL) of low carbon steel strip were obtained, e.g. YS = 461+ 418 C + 61.6 Mn + 796 P ¬– 303 S + 159 Si + 146 Cu + 204 Ni + 49.7 Cr + 1127 V + 1072 Ti + 3674 Nb – 266 Mo – 6299 B – 76.3 Al – 557 Sn – 3.54 THK – 0.00758 WID – 0.114 FT – 0.223 CT. The rolling parameters in equation included finishing temperature (FT), coiling temperature (CT), thickness (THK) and width (WID) of strip. R-Square values for the formulas predicting YS, UTS, and EL were 82.3%, 90.1%, and 75.8% respectively. These equations were validated by using another 120 hot-rolled coils. The averages of absolute values of the difference between the predicted and actual values of YS, UTS, and EL were 9.6 MPa, 7.8 MPa, and 2.7 % respectively. Correlation of chemical compositions and rolling conditions with mechanical properties was discussed in the paper.

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