Losses are an important parameter of electrical steel. The grades of electrical steel

sa tu ra tio n p o la ri za tio n [ T ]

coercivity [A/m]

0.5 1.0 1.5 2.0

1 10 100 1k 10k 100k 1000k

a m o rp h o u s

NiFe 80Ni

n a n o cr ys ta lli n e

NiFe Fe, SiFe

CoFe

soft ferrites

C rC o s te e l C o F e N i C o F e V F e C rC o

AlNiCo PtCo

N d F e B

SmCo

SOFT SEMI HARD

2.5 HARD

Fe-C FeSi - NO

FeSi - GO FeSi - HiB

amorphous (Fe) amorphous (Co)

nano

FeNiMo

Co90Fe

Co50Fe Fe-Co

FeCr Fe, FeSi6

H

[A/m]

price [Euro/kg]

0.1 1 10 100 1000

0.1 1 10 100

FeNi FeNiCr

NO SiFe 53%

GO SiFe 30%

rest 17%

ferrites 7.5%

NiFe 5%

powder 2.5%

amorph 1.5%

other 0.5%

Parameter 3% SiFe GO

FeSiB Metglas

Ni80Fe20 Permalloy

Co50Fe50 Permendur

MnZn Ferrite

Bs [T] 2.03 1.56 0.82 2.46 0.2 - 0.5

Hc [A/m] 4 - 15 0.5 - 2 0.4 - 2 160 20 - 80 P1.5T/50Hz

[W/kg]

0.83 0.27 1

P 1T/1kHz [W/kg]

20 5 10 20

µmax

 1000

20 - 80 100 - 500 100 - 1000 2 - 6 3 - 6 Frequency

range [kHz]

3 250 20 up to 1 kHz 2000

NiZn - 100 000

1900 1950 2000 year 0.1

0.5 1 5 10

core loss P1.5/50 W/kg

theoretical limit for cold rolled sheet

addition of Si Goss process Hi-B

reduced C content

greater grains

high-temperatiure annealing

decarburization of steel high-temperature

treatm ent of slabs

stress coating purifield steel

laser scribing higher Si content

reduced thickness chemical polishing

Losses are an important parameter of electrical steel. The grades of electrical steel (and of course its price) strongly depends on loss. The loss is mainly dissipated as heat thus it is wasted energy. Although efficiency of modern power transformers is as high as 99% it is

estimated that annual losses of energy just in the UK are equivalent to about 710⁶ of barrels of oil, what is equivalent to about 35 000 ton of SO₂ and 410⁶ ton of CO₂. It is estimated that annual magnetic core losses in the US amount to nearly 45 billion kWh costing about 3 billion dollars. [Moses 1990, Moses 2004].

hard

< 111 >

easy

< 100 >

medium

< 110 >

< 111 >

< 100 >

< 110 >

J [T]

H [kA/m]

2

1

10 20 30

rolling direction

< 100 >

< 1 11 >

plane (110)

tilt angle

54.7^o

rolling direction grain border

< 100 >

< 1 00 >

a) b)

inductive heating melting Fe Si B Cu

copper drum

ribbon nozle

Js [T] µmax 1000 10^-6

Metglas 2605 SA1 Fe78B13Si9 1.56 600 27

Metglas 2605 SC Fe81B13.5Si3.5C2 1.61 300 30

Metglas 2605CO Fe66Co18B15Si1 1.8 400 35

Metglas 2705 M Co69Fe4Ni1Mo2Si12B12 0.77 800 <0.5 Metglas 2714 A Co66Fe4B14Si15Ni1 0.57 1000 <0.5 Matglas 2826 MB Fe40Ni38B18Mo4 0.88 800 12

Vitrovac 6025 Co66Fe4B12Si16Mo2 0.55 600 0.3 Vitrovac 6030 Co70(FeMo)2Mn5(SiB) 0.8 300 0.3

97 98 99

25 50 75 100

amorphous SiFe

efficiency [%]

load [%]

permalloy 50NiFe

FeSi6.5

nanocrystalline

1 nm 1mm 1 mm

1000

100

10

1

H_c [A/m]

grain size

as quenched finalamorphous

Fe-Cu-Nb-Si-B compositional

fluctuations

nucleation of bcc Fe-Si

initial stage of crystallization

optimum crystalline state

Cu cluster bcc Fe-Si

amorphous Nb&B enriched

FINEMET Fe-Si-B-Nb-Cu

NANOPERM Fe-Zr-B-Cu

HITPERM FeCo-Zr-B-Cu Amorph-Co

Amorph-Fe SiFe

1.0 2.0

10⁴ 10⁵

B [T]

m

Ba-ferrite

25 cm³

Alnico 500

20 cm³

SmCO2

0.9 cm³

NdFeB

0.3 cm³ 5 mm

ferrite bonded ferrite

sintered alnico

isotropic NdFeB bonded

bonded SmCo anisotropic

NdFeB bonded

sintered NdFeB

sintered SmCo NdFeB

nanocomposites

0.5 1.0 Br [T]

0.8 1.6 Hc [kA/m]