electrical steel - MAG-COR

MAG-COR
Electrical Steel Products
Your Electrical Steel Service Center
FROM EXPERIENCE COMES KNOW-HOW
Having created the FIRST independent electrical steel service center more than
30 years ago, today we are able to offer custom slit GO and NGO to meet the
requirements of the most demanding applications.
Whether you need slit widths, cut to length or assembled cores, we can service
your requirements with prompt deliveries from our regional warehouses.
We can work with you to customize the product you need to better satisfy your application and your bottom line.
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
ELECTRICAL STEEL
MAG-COR
Electrical Steel Products
Electrical Steel is a specialty steel manufactured to develop optimum magnetic properties such as high magnetic permeability
and low core losses . This is achieved by reducing the amount of carbon present in the steel to a very low level (.003%) and adding enough silicon (up to 3.5% and higher for some special grades) to make it the principal alloying element. The result is a steel
product where the “grains” that make up its microstructure are “grown” to be about 10 times the size of the grains in regular
steel (.25” instead of .025”), resulting in lower hysteresis losses. The other component of the total core loss is due to “eddy
currents” and these are reduced by the reduction in the steel thickness.
In order to suit the requirements of specific applications in a vast variety of electrical apparatus types, Electrical Steels are produced in several classes and grades primarily graded by core losses. This is because the maximum core loss is generally the
most important characteristic taken into consideration for the design optimization of any power electric or electronic device.
The American Iron and Steel Institute (AISI) system of electrical steel grading assigns a number (known as the M-grade) to
each grade related to the core loss. The number attached to the M grade was initially set as 10 times the core loss in Watts/lb
for 29 gauge material tested at 1.5 Tesla and 60 Hertz. For example, M-19 29 gauge had a maximum core loss of 1.90 W/lb at 1.5
T and 60 H. Today this correlation is somewhat less precise because the manufacture of electrical steel has been substantially
improved with the result of a substantial reduction of the maximum core loss for each grade. In addition to the AISI system,
electrical steel manufacturers have created their own trade names to identify classes and grades of product.
Within the category of Electrical Steel, the industry has created several classes on the basis of the primary magnetic characteristic and the requirement of each specific application.
The general classes we are mostly concerned with are:
Grain Oriented. This class of Electrical Steels is obtained by processing, through rolling and annealing, a suitable steel alloy in
order to align the “grains” of its microstructure in the direction of rolling. The result is a class of steels having magnetic properties highly superior when the magnetic flux is oriented with the direction of rolling.
Non Grain Oriented. This class of Electrical Steels is obtained by processing, through rolling and annealing, a suitable steel alloy
in order to get the “grains” of its microstructure randomly aligned in all directions of the material plane. The result is a class of
steels having magnetic properties that are roughly the same independently from the orientation of the magnetic flux with respect of the direction of rolling.
These 2 classes are both “Fully Processed” meaning that the magnetic properties are completely developed at the steel manufacturing stage and the material is ready to be used without any additional processing except for some minor heat treatment
that the user may elect to employ to eliminate fabrication induced mechanical stresses.
The grading of Electrical Steel is made through a standardized test known worldwide as the Epstein Test (ASTM A343). In this
test a transformer is built in a standardized frame and subject to core loss measurements. Core losses can also be measured
with a single sheet tester. MAG-COR is able to test its materials with both methods and certified results for each specific delivered product can be supplied on request.
An additional property that must to be considered when using Electrical Steels is the insulating coating applied to the material.
A comprehensive description of insulating coating is covered by the ASTM Standard A 976 while the most used types will be
described later on for each class of steel.
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
GRAIN ORIENTED
ELECTRICAL STEEL
MAG-COR
Electrical Steel Products
Grain Oriented Electrical Steel (CRGO) is a cold
rolled special steel with a low Carbon content
and up to 3.5% of Silicon. The steel is processed
in such a way as to develop superior magnetic
properties highly oriented with the direction of
rolling, resulting in inferior properties in all other
directions.
GO is produced in different grades, suitable for
each specific application, as follows:
Grade
Nominal
Thickness
Space
Factor
W/lb
1.5 T/60Hz
W/lb
1.7 T/60Hz
M3
.009
.96
.45
.70
M4
.011
.96
.51
.74
M6
.014
.97
.66
.94
CRGO Applications.
In general, CRGO electrical steels are used in large to medium and small power transformers, distribution transformers, current transformers, reactors, audio transformers and chokes.
The selection of the most suitable grade for any given application, is based on the best combination of
the characteristics required by the specific design. Examples are the need for high induction permeability that may require higher core losses and vice-versa the imperative of low core losses may force
the use of more expensive material.
One other important characteristic to be considered is the surface insulation of CRGO as this, together with the thickness of the material, is one of the factors that influence the interlaminar eddy
current circulating across the entire stack of laminations. The types of surface insulation most common for CRGO are:
ASTM
Description
Applications
C-2
Inorganic glass like film. Withstands
stress relief annealing. Very abrasive
Wound Cores, ,distribution transformers, reactors
C-5
Inorganic with ceramic fillers applied
over C-2. Withstands stress relief annealing in controlle atmosphere.
Applications with high volts per turn
and whenever high interlaminar resistance is required
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
NON GRAIN ORIENTED
ELECTRICAL STEEL
MAG-COR
Electrical Steel Products
Non Grain Oriented Electrical Steel (CRNGO) Fully Processed is a cold rolled special steel with a low Carbon content and up to 3 % of Silicon. The steel is manufacured without any special process aiming at
developing superior magnetic properties oriented with the direction of rolling. The result is a steel
where the magnetic properties are randomly oriented and is therefore suitable for applications where
the magnetic flux may flow in any direction as is the case with rotating machines.
Other suitable applications are those where cost of material is the primary factor and the performance
is not of critical importance.
CRNGO is produced in different grades suitable for each specific application as follows:
Grade
Nominal
Electrical
W/lb
Thickness Steel Gauge 1.5 T/60Hz
M15
.014/.0185
29/26
1.45/1.60
M19
.0185/.025
26/24
1.65/2.00
M22
.0185/.025
26/24
1.80/2.10
M27
.0185/.025
26/24
1.90/2.25
M36
.0185/.025
26/24
2.00/2.35
M43
.0185/.025
26/24
2.10/2.50
M45
.0185/.025
26/24
240/2.75
M47
.0185/.025
26/24
2.80/3.20
One other important characteristic of CRNGO to be considered is the surface insulation which influences the interlaminar eddy current circulating across the entire stack of laminations. The types of surface insulation most common for CRNGO are:
ASTM
Description
Applications
C-3
Enamel or varnish coating. Will not
withstands stress relief annealing.
Medium size distribution and power
transformers, rotating machines.
C-4
Chemically treated or phosphated
surface. Withstands stress-relief
annealing
Similar applicatons as for C-3 with
stress relief annealing.
C-5
Inorganic with ceramic fillers applied over C-2. Withstands stress
relief annealing in controlled atmosphere.
Applications with high volts per turn
and whenever high interlaminar resistance is required
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
OUR PRODUCTS
MAG-COR
Electrical Steel Products
What we offer:
Grain Oriented Electrical Steel
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•
•
M2, M3, M4, M6
Thin Gauge down to .004”
Surface Insulation: C5
Dimensional Range of products & Tolerances.
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Non Oriented Electrical Steel, Fully Processed
•
•
•
M47 to M12, 24G to 30G
Thin Gauge NGO from .011” to .004”
Surface Insulation: C3/C5, others on demand
•
Close Tolerance High Precision Slitting
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•
•
•
•
•
Light gauge Electrical Steel from .004”
to .035”
Slit widths range from .375” to 18”
Individual Slit Coils Core Losses Measured and
Certified
Balanced Inventory to accommodate
Just-In-Time Delivery Programs
Monthly or weekly shipping programs with
price hold
Regional warehouses for local customer convenience
•
•
Inside Diameter of Coil: 20”/16”
Maximum Slit Width: 18”
Minimum Slit Width: .375”
Thickness Tolerances (ASTM 876/840):
.009” +.0075” -.010”
.011” +.0095” -.0120”
.014” +.0125” -.0150”
.018” +.0020” - .0020”
.025” +.0030” -.0030”
Width Tolerances (ASTM 876/840):
Up to 4.00” wide +.005” –.005”
Over 4.00” to 9.00” incl. +.007“–.007”
Over 9.00” to 15.00” incl. +.010” -.010
Over 15.00” +.016” -.016”
Maximum burr: .0008”
Maximum package weight: 10,000 lbs
Cut to Length Laminations
•
•
Square Cut from 2” to 12” wide to 2” to 120”
long
Small Runs for Prototype Development
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
WOUND & FLAT-STACK
CORES
MAG-COR
Electrical Steel Products
WOUND CORE
FLAT STACK CORE
E
g
OD
ID
D
e
W
e
e
H
f
f
E
D
F
Length
e, f, g
G
D
Inside Diameter
ID
Outside Diameter
OD
Strip Width
D
Build
E
Window Width
F
Window Length
G
M(Mean Length)=3xe+2xf+1xg
Weight Formula
WT(lbs)=DxMxStack Heightx.276xSF(Stacking Factor)
All sizes in “
Weight Formula
WT(lbs)=(OD²-ID²)xDx.217xS.F.(Stacking Factor)
All sizes in “
Toll free: 800 926 6050
email: [email protected]
FAX: 410 510 1827
[email protected]
www.mag-cor.com
Tel +1 800 926 6050
Fax +1 410 510 1827
MAG-COR
Electrical Steel Products