Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/24—Magnetic cores
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
  • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
  • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
  • H01F1/147—Alloys characterised by their composition
  • H01F1/14766—Fe-Si based alloys
  • H01F1/14775—Fe-Si based alloys in the form of sheets
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/0206—Manufacturing of magnetic cores by mechanical means
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
  • C21D8/1233—Cold rolling
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
  • C21D8/1272—Final recrystallisation annealing
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
  • C21D8/1283—Application of a separating or insulating coating

Definitions

• the invention concerns cold-rolled transformer laminations and sheets with a cubic texture.
• the invention further concerns a process for the manufacture thereof.
• the appearancein 1935 of transformer laminations with a so-called Goss texture resulted in great advances in transformer construction.
• Such laminations can be magnetized most easily in the direction of rolling andtheir magnetic properties are particularly good in the direction of rolling.
• the power loss V of a lamination of thickness 0.35 mm. is not more than 0.48 w./kg., while itsinduction B in a magnetic field of 25 AW/cm. equals 18,900 G.
• the magnetic properties are less advantageous: the power loss V is about 1.37 w./kg., whilst-B is only about 12,200 G.
• transformers Due to the poor magnetic properties in the transverse direction, only those transformers can be manufactured from transformerlaminations with aGoss texture, wherein thedirection of the magnetic'linesof force coincide with the direction of rolling of the lamination (e.g.,.sectional lamination cores).
• transformer laminations with a cubic structure which can most readily be magnetized in two directions, namelyin the direction of rolling and in the transverse direction in the plane of the sheet.
• the magnetic properties are extremely advantageous: the power loss V is 04-06 w'./kg.- in the longitudinal, as well as in the transverse direction, the initial permeability is 1,500-5 ,000 G/Oe, and the maximum permeability reaches 25,00050,000 G/Oe;
• the favorable magnetic properties are approximately equal in the longitudinal and transverse directions,which makes possible the manufacture of the various E-, U- and M-cores by simple methods;
• an alloy containing 20-40 percent of Si or, instead of part of the Si-component, aluminum, and into which also 0.050.3 percent of manganeseand a small amount of nickel can be alloyed is hot-rolled to a thickness of about 3.0 mm., then cold-rolled with three to five intermediate annealings to 0.04-0.20 mm., and finally thermally treated for a longer period (for at" least 24 hours) at 1,200-l,300 C. in a dry hydrogen atmosphere with a dew point below 50 C.;
• the cubic texture can be improved by arranging nickel alloys or nickel-containing ceramic materials near the surface of the lamination during the last thermal treatment;
• the formation'of the cubic texture can alsobe improved by carrying out the last two intermediate annealings between l,l and l,300 C.;
• the cubic texture can advantageously be influenced while respecting certain requirements in that a small amount of hydrogen sulphide is added to the gas amount of hydrogen sulphide is added to the gas atmosphere in the course of the final thermal treatment;
• transformer laminations with .a cubic structure starting from a steel ingot crystallized directionally -by suitable methods, after -:an advantageously chosen hot-rolling, subsequent thermal treatment and cold-rolling performed with intermediate treatment, if during the final thermal treatment a dry hydrogen atmosphere or a vacuum is applied;
• a finished,.Goss-textured lamination can be rolled further .in twosteps-with intermediate annealing, after which the final thermal treatment described under (a) is to be used;
• transformer laminations can be mass produced in a simple manner and at low cost.
• the invention is based on the following findings:
• the number of particles in the cubic texture position, formed during the primary recrystallization is increased so that the secondary recrystallization can consequently be carried out at lower temperatures, whereby the particle size becomes more uniform. All this has an ad vantageous effect on the magnetic properties, and the quantity of cubic texture-oriented particles reaches 80-90 percent;
• the crystal surface and crystal boundary energies are considerably varied during the final thermal treatment, i.e., these values are influenced favorably relative to the cubic texture formation;
• the action of the gallium alloy can be improved by adding certain quantities of one or more further metals (e.g., nickel or copper).
• the best way of avoiding sticking together of the windings and the oxidation or soiling of the lamination surface during the final thermal treatment is to interpose or insert a wire or strip, consisting of an iron alloy containing 0.5-6 percent by weight of aluminum.
• the cold-rolled transformer laminations with a cubic texture according to the invention contain a maximum of 4 percent by weight of silicon, alloyed with 0.000l-0.20 percent by weight, preferably 0.04-0.06 percent by weight of gallium, 0.0.5 percent by weight, preferably 0.2-0.4 percent by weight of nickel, 0.5 percent by weight, preferably 02-03 percent by weight of copper.
• the invention further concerns a method for the manufacture of such cold-rolled transformer laminations and sheets with a cubic texture, by micro-alloying the iron-silicon base material by successive thermal shaping, descaling, coldrolling, intermediate annealing, final rolling and final thermal treatment of the ingot obtained.
• the process according to the invention is more simple and may be carried out with higher technological tolerances;
• laminations as well as finished cores and parts can be subjected to the final thermal treatment
• the process can be carried out by using known apparatus for the manufacture of transformer laminations with a Goss texture.
• Example l An iron-silicon alloy with a nominal content of 3.2 percent of silicon, 0.05 percent of gallium and 0.35 percent of nickel with a very small content of impurities, is produced in an induction vacuum furnace from a pure iron charge of good quality, from metallic silicon with a silicon content exceeding 98.5 percent and with an aluminum content of less than 0.5 percent, as well as from metallic nickel.
• the impurities of the alloy do not exceed the following values: 0.05 percent of carbon, 0.015 percent of sulphur, 0.03 percent of chromium, 0.03 percent of molybdenum, 0.93 percent of vanadium, 0.03 percent of tungsten, 0.01 percent of titanium and 0.005 percent of oxygen.
• the ingot is hot-rolled to a thickness of 3 mm. at a starting temperature of l,l00-l,l50 C.
• the temperature of the lamination is kept above 900 C. before the last pass.
• the scale is removed from the hot-rolled lamination by means of a pickling agent containing sulphuric acid and the lamination is then annealed for 2 hours at 800 C. in a humid hydrogen atmosphere with a dew point of +20 C.
• the lamination is then cold-rolled in several passes to a thickness of 0.80 mm. and, after degreasing, thermally treated for 2 hours at a temperature of 850 C. in a hydrogen atmosphere with a dew point of 30 C.
• the lamination is then cold-rolled in several passes to a thickness of 0.30 mm. and, after degreasing, thermally treated for 2 hours at a temperature of l,000 C. in a vacuum of 10 Torr.
• the lamination the surface of which is metallically pure, is cold-rolled with polished rollers in several passes to a thickness of 0. 10 mm.
• the thus prepared lamination coil is subjected to a thermal treatment in a vacuum furnace in a vacuum of 10 Torr in such a way that during heating the material is kept hot for 2 hours between 550 and 700 C.; the temperature is then raised to l,l00 C. and kept for 20 hours at this value. After completing the thermal treatment, the charge together with the furnace is cooled to 500 C. percent of the particles of the lamination thus produced are in the cubic texture position; the initial permeability of the lamination is 4,200 G/Oe and the maximum permeability 45,000 G/Oe.
• Example 2 A lamination cold-rolled according to Example 1 to 3 mm. and produced from a steel ingot, the composition of which corresponds to that of Example 1, is descaled in a pickling agent containing sulphuric acid and then subjected for 2 hours to thermal treatment at 800 C. in a humid hydrogen atmosphere with a dew point of 20 C.
• the lamination is then cold-rolled to L0 mm. in several passes and, after degreasing, thermally treated for 2 hours at a temperature of 850 C. in a hydrogen atmosphere with a dew point of30 C.
• the lamination is then cold-rolled in several passes to a thickness of 0.45 mm. and then-after degreasing-subjected for 2 hours to thermal treatment at a temperature of 1,000 C. in a vacuum of 10' Torr.
• the lamination the surface of which is metallically pure, is finally cold-rolled with polished rollers in several passes to a thickness of 0.20 mm. Thereafter one proceeds as in Example 1.
• Example 3 One proceeds as described in Example 1 but the silicon content ofthe alloy is adjusted to 2.6 percent by weight, the nickel content to 0.3 percent by weight and the gallium content to 0.05 percent by weight.
• Example 4 One proceeds as described in Example 1 but the final thermal treatment is carried out for 5 hours.
• the initial permeability p of the lamination thus obtained is 3,300 G/Oe and the maximum permeability 24,500 G/Oe.
• Example 5 One proceeds as described in Example I but the final thermal treatment is carried out in a dry hydrogen atmosphere (dew point below 50 C.) at l,200 C. in such a way that this temperature is maintained for 20 hours. In this manner a lamination is obtained, the initial permeability of which is 3,700 G/Oe and the maximum permeability 37,000 G/Oe.
• Example 6 One proceeds as described in Example 1 except that prior to the final thermal treatment the desired core sheets are cut out from the lamination, and the thermal treatment is carried out in such a way that during cooling and on reaching 700 C. the core sheets are exposed to the action of the magnetic field of a field intensity of 10-20 Oe. The initial permeability i of the maximum permeability 63,000 G/Oe.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Electromagnetism (AREA)
• Manufacturing & Machinery (AREA)
• Thermal Sciences (AREA)
• Dispersion Chemistry (AREA)
• Soft Magnetic Materials (AREA)
• Manufacturing Of Steel Electrode Plates (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=11001351

Family Applications (1)

Country Status (12)

Cited By (3)

Citations (6)

• 1969
  • 1969-06-23 CS CS4414A patent/CS162685B2/cs unknown
  • 1969-06-23 YU YU01602/69A patent/YU160269A/xx unknown
  • 1969-06-26 CH CH981469A patent/CH547541A/de not_active IP Right Cessation
  • 1969-07-01 RO RO60399A patent/RO55939A/ro unknown
  • 1969-07-07 US US839683A patent/US3650851A/en not_active Expired - Lifetime
  • 1969-07-11 AT AT671269A patent/AT308163B/de not_active IP Right Cessation
  • 1969-07-15 FR FR6924076A patent/FR2013111A1/fr not_active Withdrawn
  • 1969-07-15 GB GB35648/69A patent/GB1271459A/en not_active Expired
  • 1969-07-16 BE BE736157D patent/BE736157A/xx not_active IP Right Cessation
  • 1969-07-16 SE SE10074/69A patent/SE342845B/xx unknown
  • 1969-07-16 PL PL1969134866A patent/PL80148B1/pl unknown
  • 1969-07-17 DE DE19691936425 patent/DE1936425B2/de active Pending

Patent Citations (6)

Also Published As

Similar Documents