| KRYFS LAMINATIONS
PVT. LTD: Manufacturers of CRGO Transformer Core
Laminations & CRGO Strips in India. |
 |
TECHNICAL DETAILS : |
|
CRGO or Cold Rolled Grain Oriented
Steel is available in various grades (generally
called M3, M4, M5 & M6). Major international
standards such as Japanese (JIS), American (ASTM),
German (DIN) and British Standards are given in
table 1 which specify grade, thickness, Watt
Losses and Magnetic Flux density.
| |
 |
|
IMPORTANT ELECTRICAL PROPERTIES OF
CRGO |
|
Table 1 - Grain Oriented Electrical
Steel strips
| |
| Japanese |
| JIS C 2553 (1986)
|
| Classification
|
Density
(kg/dm) |
Iron
Loss
(W/kg)
W17/50 |
Magnetic
Flux
Density (T) B |
| Symbol |
Thickness
mm
|
| 27
P 100 |
0.27 |
7.65 |
1.00 max. |
1.85 |
| 27
P 100 |
1.00 max. |
| 27
G 120 |
1.20 max. |
1.78 |
| 27
G 130 |
1.30 max. |
| 27
G 140 |
1.40 max. |
1.75 |
| 30
P 110 |
0.30 |
1.10 max. |
1.85 |
| 30
P 120 |
1.20 max. |
| 30
G 130 |
1.30 max. |
1.78 |
| 30
G 140 |
1.40 max. |
| 30
G 150 |
1.50 max. |
1.75 |
| 35
P 125 |
0.35 |
1.25 max. |
1.85 |
| 35
P 135 |
1.35 max. |
| 35
G 145 |
1.45 max. |
1.78 |
| 35
G 155 |
1.55 max. |
| 35
G 165 |
1.655 max. |
1.75 | |
|
| British |
| BS 601 Part 2 (1973)
|
| Maximum specific total loss at a
peak magnetic flux density of 1.5T and a frequency
of 50 Hz. |
Grade
|
Maximum specific total loss W/kg
|
35M6
|
1.11 |
30M6
|
1.07 |
30M5
|
0.97 |
28M5
|
0.95 |
28M4
|
0.89 |
| |
| |
|
| USA |
| AISI ( 1983 )
|
| MAXIMUM CORE LOSSES - Electrical
Steels Grain Oriented Full Processed ASTM A665
|
ASTM
Type
|
Former
AISI
Type
|
Thickness
|
Maximum Core Loss at 15 kg (1.5 T)
|
| W /
lb |
W /kg
|
Inch
|
mm |
60Hz
|
50Hz
|
60Hz
|
50Hz |
27G053
|
M-4 |
0.0106
|
0.27 |
0.53 |
0.40 |
1.17 |
0.89 |
30G058
|
M-5 |
0.0118 |
0.30 |
0.58 |
0.44 |
1.28 |
0.97 |
35G066
|
M-6 |
0.0138 |
0.35 |
0.66
|
0.50 |
1.46 |
1.11 | | |
|
|
IMPORTANT PHYSICAL PROPERTIES OF
CRGO | |
Density gm/c3
|
7.65 |
Silicon content %
|
3.10 |
Resistivity micro
Ohm-centimeter
|
48.00 |
Ultimate Tensile Strength 0° to
Rolling Direction Kg/mm2
|
32.60 |
Ultimate Tensile Strength 90° to
Rolling Direction Kg/mm2
|
38.20 |
| Stacking factor % M4 (.27
mm) |
96.00 |
| Stacking factor % M5 (.30
mm) |
96.50 |
| Stacking factor % M6 (.35
mm) |
97.00 |
| CRGO materials come either in the
form of coils or sheets. Table 2 gives details of
dimensions and tolerances as per JIS C
3553. | |
|
|
DIMENSIONS &
TOLERANCES | |
| COILS |
Thickness |
0.18 mm (0.0071 in.
) |
| 0.20 mm (0.0079 in.), 0.23 mm
(0.0091 in. ) |
| 0.27 mm (0.0106 in.), 0.30 mm
(0.0118 in. ) |
| 0.35 mm (0.0138 in.) |
Width
(Standard
width available with range)
|
914 mm (36 in.), and 1000 mm (39 in.
) |
| from 50 mm(2 in.), to 1.050mm (41
in. ) |
Inside Coil Diameter
|
508 mm (20 in. ) |
| Sheets |
Thickness |
0.30 mm (0.0118 in.), 0.35 mm
(0.0138 in. ) |
| Width |
914 mm (36 in.), and 1000 mm (39 in.
) |
| Length |
Length will be available according
to negotiation | |
|
| Tolerances in Dimensions & Shape -
conform to JIS C 2553. |
Width
mm
|
Thickness mm |
TOLERANCE |
| Thickness mm |
Deviation of thickness
in transverse direction
mm
|
Width
mm
|
Camber in any 2 metres
(Slit
Products)
mm
|
Shear Burr mm
|
150
or
under |
0.18
0.20
0.23
0.27
0.30
0.35
|
+0.02
+0.02
+0.02
+0.03
+0.03
+0.03
|
0.02 or under
|
+0.20 |
1.0 or
under |
0.05
or
unde |
over 150
to 400 |
0.18
0.20
0.23
0.27
0.30
0.35
|
+0.02
+0.02
+0.02
+0.03
+0.03
+0.03
|
0.02
or under
|
+0.30 |
over 400
to 750
|
0.18
0.20
0.23
0.27
0.30
0.35
|
+0.02
+0.02
+0.02
+0.03
+0.03
+0.03
|
0.03
or under
|
+0.50 |
| over 750 |
0.18
0.20
0.23
0.27
0.30
0.35
|
+0.02
+0.02
+0.02
+0.03
+0.03
+0.03
|
0.03
or under
|
+0.6
0 | |
| Besides the
Watt Losses at specific flux densities of 1.5 T
and 1.7 T CRGO manufacturers also give curves of
indicating Watt Losses ad A.C. Magnetization at
various flux densities. These curves are of
immense help to Transformer designers, and
available on
request. | |
|
Hi - B CRGO MATERIALS : |
|
Conventional CRGO materials (M4, M5,
M6) are used regularly for cores in Transformers.
However recently due to environmental protection,
energy savings are becoming a very important
factor and minimizing care loss in transformers is
becoming a must. Nippon Steel Corporation has come
out with low loss Hi-B materials, which guarantee
low Watt Losses at 1.5 Tesla flux density. Such
materials are called Hi-B materials. Table 3 gives
magnetic properties of Hi-B material. Popular Hi-B
grades used in India are 23 MOH &
27 MOH
Watt.
| |
|
Hi - B CRGO MATERIALS
: | |
Thickness
|
Grade |
Core Loss
|
Lamination
Factor |
Max.
|
Typical
|
Typical
|
Typical |
| mm |
mil |
W
(W/Kg) |
W
(W/Kg) |
W
(W/Kg) |
W
(W/Kg) |
W
(W/Kg)
|
B
(T)
|
% |
| 0.23 |
9 |
23ZDKH85 |
0.85
|
0.57
|
0.78
|
0.34
|
0.46
|
1.91
|
97.5 |
| 23ZDKH90 |
0.90
|
0.58
|
0.80
|
0.35
|
0.48
|
1.91 |
| 23ZDMH85 |
0.85
|
0.57
|
0.78
|
0.34
|
0.46
|
1.91 |
97.4 |
| 23ZDMH90 |
0.90
|
0.59
|
0.81
|
0.35
|
0.48
|
1.91 |
| 23ZH90 |
0.90
|
0.63
|
0.87
|
0.37
|
0.51
|
1.92
|
97.7 |
| 23ZH95 |
0.95
|
0.64
|
0.90
|
0.38
|
0.53
|
1.92 |
| 23M-OH |
1.00
|
0.66
|
0.93
|
0.39
|
0.54
|
1.92 |
| 0.27 |
11 |
27ZDKH90 |
0.90
|
0.62
|
0.84 |
0.38
|
0.53
|
1.92 |
98.0 |
| 27ZDKH95 |
0.95
|
0.65
|
0.88
|
0.39
|
0.52
|
1.91 |
| 27ZDMH90 |
0.90
|
0.62
|
0.84
|
0.38
|
0.53
|
1.91
|
97.9 |
| 27ZDMH95 |
0.95
|
0.65
|
0.88
|
0.39
|
0.53
|
1.91 |
| 27ZH95 |
0.95
|
0.69
|
0.93
|
0.41
|
0.55
|
1.91 |
98.1 |
| 27M-OH |
1.03
|
0.72
|
0.99
|
0.43
|
0.59
|
1.91 |
| 27M-1H |
1.09
|
0.74
|
1.03
|
0.44
|
0.61
|
1.91 |
| 0.30 |
12 |
30ZH100 |
1.00
|
0.73
|
0.98
|
0.44
|
0.58
|
1.92
|
98.3 |
| 30M-OH |
1.05
|
0.74
|
1.01
|
0.44
|
0.60
|
1.91 |
| 0.35 |
11 |
35M-1H |
1.16
|
0.85
|
1.13
|
0.52
|
0.68
|
1.92 |
98.5 |
| 35M-2H |
1.22
|
0.90
|
1.19
|
0.54
|
0.73
|
1.92 | |
A. K. Steel Corp. of USA ( formally
ARMCO)has also come out with their own brand of
low loss CRGO called Trancor H-0 and Trancor H-1.
The Watt Losses are as follows :
CORE
LOSSES | |
ARMCO TRAN. CORE
|
THICKNESS INCHES (mm) |
WATTS PER KG 60 Hz 1.7 T
|
WATTS PER KG 50 Hz
1.7
T |
| H-0 |
.009 ( .23 ) |
1.32 |
1.01 |
| H-1
|
.011 ( .27 ) |
1.46 |
1.11 | |
| |
| |
