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Relationship between rolling direction and texture in thin grain-oriented 3% silicon sheets
N
ELSEVIER
Journalof magnetism and magnetic ~ H materials
•i• Journal of Magnetism and Magnetic Materials 196-197 (19991 344-345
Relationship between rolling direction and texture in thin grain-oriented 3% silicon sheets M. Nakan&'*, K. Ishiyama h, K.I. Arai b, H. Fukunaga ~ ~ Faculty o/'Engineering. Department qi Eh,clrical and Electronic Engineering, Nagasa[~i Unirersi(r, Naga.~'aki $52-b¢521. ,/apart h Tohoku (')urer,siO &'ndai 9h'O-77, d~q)cm
Abstract We investigated the effect of the rolling direction and the texture of a mother material on the texture of thin sheets. It was found that the [0 0 1] orientation of thin silicon sheets is affected by a roiling direction rather than by a texture of the mother material. '~i 1999 Elsevier Science B.V. All rights reserved. Kevwords: Rolling direction; [0 0 1] orientation (1 1 01 grain: Hot-rolled silicon steel
We have already reported that thin grain-oriented 3% silicon steel sheets, whose iron loss at 1.3 T, 50 Hz under the applied tensile strength of 2 kg/mm z is 0.38 W/kg, can be produced by the three-stage rolling lnethod without inhibitors [1]. However, the average ~. angle (the angle between the [0 0 1] axis and the rolling direction in the (1 0 0) plane) of these sheets was about 4' 5 , which is larger than the average ~ angle of 3' reported in conventional grain-oriented silicon steels. Thus, a reduction in the ~ angle in the thin silicon sheets is expected to achieve a further decrease in iron loss. Some experiments about the relationship between cold rolling direction and the orientation of the resultant [0 0 1] axis have already been reported in conventional grain-oriented silicon steels [2,3]. In such experiments, however, it is difficult to neglect the effect of inhibitors in the control of final texture. In this report, we examined the effects of cold rolling direction and the texture of mother materials on the [ 0 0 1] orientation of the resultant thin grain-oriented silicon sheets. The texture coefficient [4] of a hot-rolled silicon steel was measured with etching the hot-rolled silicon steel
* Corresponding author. Tel.: + 81-95-847-6825: fax: + 8195-846-7379: e-mail: nakano(~:ec.nagasaki-u.ac.jp.
and is shown ill Fig. 1 as a function of the depth from the surface. The texture coefficient (TCI for the {ho ko/nl plane is defined as T C I h , ko I,I = l,'n × ,lIho ko Io t'IJho ko Io },
where llhi ki 10 and l~(hi k, li) are the measured integrated X-ray intensities from (hi ki IJ plane in the sample and the standard powder sample, respectively. Further, n is the number of planes observed for the standard powder sample under a given experimental condition. As the depth is normalized by the thickness of the steel, the values of 1.0 and 0.5 correspond to the surface and the center of the hot-rolled silicon steel, respectively. As seen in Fig. 1, strong ( 1 1 0) texture exists in the vicinity of the surface of hot-rolled silicon steel. Small strips (mother stripsk 100ram in length and 20 mm in width, were cut from a large hot-rolled sheet with varying the angle 0 between the longitudinal direction of a mother strip and the hot-rolled direction, as shown in Fig. 2. Subsequently, a cold-rolled grainoriented, 80 lalrl in thickness, were prepared from the strip using the three-stage cold-rolling method reported previously [1]. In the three-stage cold-rolling method. the direction of the cold-rolling was set to the longitudinal direction of the strip. As we have already confirmed
031)4-8853/99/$ - see front matter ,c. 1999 Elsevier Science B.V. All rights reserved PII: $ 0 3 0 4 - 8 85 3 ( 9 8 ) 0 0 7 4 1 -0
345
M Nakano et al./Journal of Magnetism and Magnetic Materials 196-197 (1999) 344-345 6, i i i / H o t - r o l l e O silicon steel
,z
2.(
i
I
O (110) • :(200',
•
1.5
-u [
Three-stage cold-rolling method
<-"
I
o
1.0
L 0
_1 1
I
I
L
0.5
0.75
1.0
"~
,
, 20
i 40
0
,
i 60
,
i 80
100
Angle e3 between the longitudinal direction and the hot-rolled direction (deg.)
I
Normalized depth from thickness
Fig. 1. Texture coefficient of hot-rolled silicon steel as a function of depth from one of surfaces• The depth is normalized by the thickness of the steel. The values of 1.0 and 0.5 correspond to one of the surfaces and the center of the hot-rolled silicon steel, respectively.
Fig. 3. Magnetic induction under applied field of 800 A/m, B8 and coercive force Hc in thin 3% silicon sheets obtained by three-stage rolling method as a function of angle, 0, between longitudinal direction and hot-rolled direction of a mother strip•
~,~
Hot-rolled steels
Three-stage cold-rolling method
0
~5
20
40
60
80
"E
100
Angle • between the longitudinal direction and the hot-rolled direction (deg.)
Fig. 4. ct angle and area percentage of (1 1 0) grains in thin silicon sheets obtained by three-stage cold-rolling method as a function of angle, 0, between longitudinal direction and hotrolled direction of a mother strip. M o t h e r strips
Fig. 2. Method of preparing mother strips from a hot-rolled silicon steel.
that the [0 0 1] orientation of the (1 1 0) texture in the mother strips is almost parallel to the hot-rolled direction, 0 agrees with the angle between the cold-rolling and the [0 0 1] orientation of the corresponding mother strips• The recrystallized texture of the thin sheets was observed by means of X-ray diffraction and etchpits. The static coercive force and the magnetic induction were measured with a D C B - H loop tracer for a ribbon with the dimension of 100 mm in length and 5-7 mm in width. Fig. 3 shows the induction at 8 0 0 A / m B8 and the coercive force Hc of thin silicon sheets made from the above-mentioned mother strips. It was found that the magnetic properties (B8, He) do not depend on 0 except 0 = 90 °. To investigate this result in more detail, the area percentage of (1 1 0) grains and ~t angle of the above samples were observed (displayed in Fig. 4). It was
clarified that thin silicon sheets covered with (1 1 0)[0 0 1] texture can be obtained at the angles between 0 ° and 75 °. In addition, e angle became almost the same value of approximately 4 °. Therefore, it can be concluded that the [0 0 1] orientation of thin silicon sheets is affected by a rolling direction rather than by a texture of a hot-rolled silicon steel. Namely, an investigation of the rolling method in three-stage cold-rolling method would be needed for decrease in e angle.
References [-1] M. Nakano, K. Ishiyama, K.I. Arai, H. Fukunaga, J. Appl. Phys. 81 (1997) 3754. [2] M. Shinozaki, I. Matoba, T. Kan, T. Gotoh, Trans. JIM 19 (1978) 85. [3] J. Harase, R. Shimizu, N. Takahashi, J. Japan Inst. Metals 54 (1990) 381. [4] C.S. Barrett, T.B. Massalsk, Structure of Metals, 3rd ed., McGraw-Hill, New York, 1966, p. 205.
ELSEVIER
Journalof magnetism and magnetic ~ H materials
•i• Journal of Magnetism and Magnetic Materials 196-197 (19991 344-345
Relationship between rolling direction and texture in thin grain-oriented 3% silicon sheets M. Nakan&'*, K. Ishiyama h, K.I. Arai b, H. Fukunaga ~ ~ Faculty o/'Engineering. Department qi Eh,clrical and Electronic Engineering, Nagasa[~i Unirersi(r, Naga.~'aki $52-b¢521. ,/apart h Tohoku (')urer,siO &'ndai 9h'O-77, d~q)cm
Abstract We investigated the effect of the rolling direction and the texture of a mother material on the texture of thin sheets. It was found that the [0 0 1] orientation of thin silicon sheets is affected by a roiling direction rather than by a texture of the mother material. '~i 1999 Elsevier Science B.V. All rights reserved. Kevwords: Rolling direction; [0 0 1] orientation (1 1 01 grain: Hot-rolled silicon steel
We have already reported that thin grain-oriented 3% silicon steel sheets, whose iron loss at 1.3 T, 50 Hz under the applied tensile strength of 2 kg/mm z is 0.38 W/kg, can be produced by the three-stage rolling lnethod without inhibitors [1]. However, the average ~. angle (the angle between the [0 0 1] axis and the rolling direction in the (1 0 0) plane) of these sheets was about 4' 5 , which is larger than the average ~ angle of 3' reported in conventional grain-oriented silicon steels. Thus, a reduction in the ~ angle in the thin silicon sheets is expected to achieve a further decrease in iron loss. Some experiments about the relationship between cold rolling direction and the orientation of the resultant [0 0 1] axis have already been reported in conventional grain-oriented silicon steels [2,3]. In such experiments, however, it is difficult to neglect the effect of inhibitors in the control of final texture. In this report, we examined the effects of cold rolling direction and the texture of mother materials on the [ 0 0 1] orientation of the resultant thin grain-oriented silicon sheets. The texture coefficient [4] of a hot-rolled silicon steel was measured with etching the hot-rolled silicon steel
* Corresponding author. Tel.: + 81-95-847-6825: fax: + 8195-846-7379: e-mail: nakano(~:ec.nagasaki-u.ac.jp.
and is shown ill Fig. 1 as a function of the depth from the surface. The texture coefficient (TCI for the {ho ko/nl plane is defined as T C I h , ko I,I = l,'n × ,lIho ko Io t'IJho ko Io },
where llhi ki 10 and l~(hi k, li) are the measured integrated X-ray intensities from (hi ki IJ plane in the sample and the standard powder sample, respectively. Further, n is the number of planes observed for the standard powder sample under a given experimental condition. As the depth is normalized by the thickness of the steel, the values of 1.0 and 0.5 correspond to the surface and the center of the hot-rolled silicon steel, respectively. As seen in Fig. 1, strong ( 1 1 0) texture exists in the vicinity of the surface of hot-rolled silicon steel. Small strips (mother stripsk 100ram in length and 20 mm in width, were cut from a large hot-rolled sheet with varying the angle 0 between the longitudinal direction of a mother strip and the hot-rolled direction, as shown in Fig. 2. Subsequently, a cold-rolled grainoriented, 80 lalrl in thickness, were prepared from the strip using the three-stage cold-rolling method reported previously [1]. In the three-stage cold-rolling method. the direction of the cold-rolling was set to the longitudinal direction of the strip. As we have already confirmed
031)4-8853/99/$ - see front matter ,c. 1999 Elsevier Science B.V. All rights reserved PII: $ 0 3 0 4 - 8 85 3 ( 9 8 ) 0 0 7 4 1 -0
345
M Nakano et al./Journal of Magnetism and Magnetic Materials 196-197 (1999) 344-345 6, i i i / H o t - r o l l e O silicon steel
,z
2.(
i
I
O (110) • :(200',
•
1.5
-u [
Three-stage cold-rolling method
<-"
I
o
1.0
L 0
_1 1
I
I
L
0.5
0.75
1.0
"~
,
, 20
i 40
0
,
i 60
,
i 80
100
Angle e3 between the longitudinal direction and the hot-rolled direction (deg.)
I
Normalized depth from thickness
Fig. 1. Texture coefficient of hot-rolled silicon steel as a function of depth from one of surfaces• The depth is normalized by the thickness of the steel. The values of 1.0 and 0.5 correspond to one of the surfaces and the center of the hot-rolled silicon steel, respectively.
Fig. 3. Magnetic induction under applied field of 800 A/m, B8 and coercive force Hc in thin 3% silicon sheets obtained by three-stage rolling method as a function of angle, 0, between longitudinal direction and hot-rolled direction of a mother strip•
~,~
Hot-rolled steels
Three-stage cold-rolling method
0
~5
20
40
60
80
"E
100
Angle • between the longitudinal direction and the hot-rolled direction (deg.)
Fig. 4. ct angle and area percentage of (1 1 0) grains in thin silicon sheets obtained by three-stage cold-rolling method as a function of angle, 0, between longitudinal direction and hotrolled direction of a mother strip. M o t h e r strips
Fig. 2. Method of preparing mother strips from a hot-rolled silicon steel.
that the [0 0 1] orientation of the (1 1 0) texture in the mother strips is almost parallel to the hot-rolled direction, 0 agrees with the angle between the cold-rolling and the [0 0 1] orientation of the corresponding mother strips• The recrystallized texture of the thin sheets was observed by means of X-ray diffraction and etchpits. The static coercive force and the magnetic induction were measured with a D C B - H loop tracer for a ribbon with the dimension of 100 mm in length and 5-7 mm in width. Fig. 3 shows the induction at 8 0 0 A / m B8 and the coercive force Hc of thin silicon sheets made from the above-mentioned mother strips. It was found that the magnetic properties (B8, He) do not depend on 0 except 0 = 90 °. To investigate this result in more detail, the area percentage of (1 1 0) grains and ~t angle of the above samples were observed (displayed in Fig. 4). It was
clarified that thin silicon sheets covered with (1 1 0)[0 0 1] texture can be obtained at the angles between 0 ° and 75 °. In addition, e angle became almost the same value of approximately 4 °. Therefore, it can be concluded that the [0 0 1] orientation of thin silicon sheets is affected by a rolling direction rather than by a texture of a hot-rolled silicon steel. Namely, an investigation of the rolling method in three-stage cold-rolling method would be needed for decrease in e angle.
References [-1] M. Nakano, K. Ishiyama, K.I. Arai, H. Fukunaga, J. Appl. Phys. 81 (1997) 3754. [2] M. Shinozaki, I. Matoba, T. Kan, T. Gotoh, Trans. JIM 19 (1978) 85. [3] J. Harase, R. Shimizu, N. Takahashi, J. Japan Inst. Metals 54 (1990) 381. [4] C.S. Barrett, T.B. Massalsk, Structure of Metals, 3rd ed., McGraw-Hill, New York, 1966, p. 205.