DE2203830B2 - USE OF CAST STEEL AS AN ACTIVE INGREDIENT FOR THE MANUFACTURE OF POLES IN ELECTRIC MACHINERY - Google Patents

Description

as a material for the production of pole masses in electrical machines

2. Use of cast steel according to claim 1, consisting of

20th

up to 0.3% carbon,
0.25 to 0.45% silicon,
0.5 to 0.9% manganese,
2, up to 2.5% nickel,
0.3 to 0.45% chromium,
0.4 to 0.6% molybdenum,
Remainder iron

for the purpose of claim 1.

Steel grade

Designation DIN

Material-

3 °

35

The invention relates to the use of cast steel with high magnetic permeability and high Elasticity limit, which its mechanical and magnetic properties even after heating, for example as a result of brazing.

The development and manufacture of large electrical machines has led to using cast steel improved elasticity limits for executing massive poles * .: · looking through their mass and speed of rotation are exposed to considerable mechanical stresses.

There are several types of cast steel that have the required mechanical properties for heavy-duty applications electrical material correspond; but a decrease in the ma-magnetic was observed for all these types of cast steel Induction for a field strength of:

number 25 A / cm 50 A / cm 100 A / cm

GS 38 GS 45 GS 52 GS 60

1.0416
1.0443
1.0551
1.0553

1.45
1.40
1.35
1.30

1.60

1.55
1.55
1.50

1.75
1.70
1.70
1.65

(1 Tesla = ΙΟ ⁴ Gauss)

DIN: German industry standard

It is even possible to establish a relationship between magnetic induction and Brinell hardness. For example, with a field strength of 25 A / cm, the magnetic induction is sufficient for something more than 1.5 T for 130 Brinell to a little less than 1.31 door 210 Brinell for non-alloyed and simple standardized steel samples.

The study of the influence of elements that normally did not alloy in an ordinary one Steel shows that the best magnetic properties are for the lowest carbon and manganese contents are obtained, which still allow perfect steel castings to be obtained.

For example, AC machine housings have been made of cast steel with high magnetic permeability with a tensile strength of the order of 40 to 45 DaN / mm (kg / mm ² ) on a regular basis for several years. The following table shows the magnetic permeability in Gauss for a steel with C ₁ Mn and Si in the specified ratios (in% by weight).

Magnetic field in A / cm

Details of the designer

stole
C.

15th 29 60 120 250 13 500 15 500 17000 18 300 20000

Mn

Si

14 200

0.113 0.64 0.61

15 800

17 200

18 600

20400

When cast steel with an elastic limit higher than 45 DaN / mnr (kg / mm x ¹ ) was examined, a decrease in the magnetic properties was found. (Magnetic induction is expressed in Gauss.)

Mn

Si

25 A / cm

50 A / cm

100 A / cm

0.332 1.50 0.38 73.3 45.3 15th 12,400 15,100 17,150 0.357 1.49 0.40 73.3 46.0 14th 12,600 14,800 17,100 0.408 1.12 0.91 81.5 47.1 13th 11,900 14.350 16,600 0.402 0.83 0.41 76.9 48.8 17th 13,700 15400 17,000

ή ,: tensile strength in DaN / mm ^? (kg / mm ² )

S _s : elastic limit in DaN / mm ² (kg / mm ² )

δ: elongation in %

The investigation of steel with 2.50% Ni has shown very satisfactory magnetic properties. However, this steel does not have the same elastic limit. the more so as the steel must also retain its mechanical properties if it is briefly heated to a temperature of the order of 700.degree. C. , which corresponds to a temperature which is reached during brazing.

Steel - ^ -
0.24

edited for

Mn

Si

Ni

(in% by weight)

048 0.36 2.51

a = 63.7 DaN / mm ² (kg / mm ² ) ös = 37.20 DaN / mm ² (kg / mm ² ) δ = 26.3%

The excitation in Tesla is with a permeability meter Illiovici - model C measured

Field strength 5.50 7.50 10 15 25 50 100 150 200 300 400

in A / cm

Excitation in T 0.56 0.84 1.08 1.36 1.55 1.69 1.82 1.93 1.98 2.04 2.08

The object of the invention is therefore the use of cast steel as a material for the production of To propose pole masses, in spite of the heating in the case of a brazing of a solid piece in each With regard to a high elastic limit and at the same time a high magnetic permeability is guaranteed

The steel casting to be used according to the invention has the composition specified in claim 1. One A steel casting composition to be used preferably according to the invention includes claim 2.

Such cast steel to be used according to the invention ensures the following mechanical properties:

tensile strenght

Elastic limit at 2%
permanent elongation

> 65 DaN / mm ² (kg / mm ² ) >, 45 DaN / mm ² (kg / mm ² ) elongation in%
Impact resistance KCU

»16

^ 7 DaJ / cnr (mkg / cm ² )

and the following magnetic properties:

For a magnetic field 50 A / cm 150 A / cm 300 A / cm of:

An excitation of: 1.60 T 1.85 T 1.92 T

This SiahiguS to be used according to the invention is carried out at a temperature of 1600 C using conventional manufacturing processes, for example in an electric arc furnace, melted and for the production of pole masses in electrical machines, in particular Generators, used

Claims (1)

Patent claims:
1. Use of cast steel, consisting up to 0.3% carbon,
0.2 to 1.0% silicon,
0.3 to 1.2% manganese,
2 to 3% nickel,
0.3 to 1.0% chromium,
0.2 to 1.0% molybdenum,
Remainder iron gnetic properties, which is why they cannot be used was. Magnetic Permeability Studies _from different types of cast steel result for one and that- same magnetic field that magnetic induction depending on the increase in mechanical Properties decreases In the following table, which is an excerpt from "Stahlguß, Edition 1966, page 142", the ίο depending on magnetic induction in Tesla Field strengths of 25 A / cm, 50 A / cm, 100 A / an for non-alloy steels with better mechanical properties shown