Classifications

• • 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
  • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
• • 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
  • C21D6/00—Heat treatment of ferrous alloys
  • C21D6/008—Heat treatment of ferrous alloys containing Si
• • 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
  • C21D8/1205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular fabrication or treatment of ingot or slab
• • 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
  • C21D8/1222—Hot 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
  • C21D8/1261—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 following hot rolling
• • 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
  • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• • 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
  • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
• • 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
• • 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
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
• • 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

Definitions

• non-grain-oriented electrical sheet is understood to mean a steel sheet or a sheet steel strip which, regardless of its texture, falls under the sheets mentioned in DIN EN 10106, the loss anisotropy of which does not exceed the maximum values specified in DIN EN 10106.
• electrical sheet and “electrical steel” are used synonymously.
• J2500 or "J5000” in the following denote the magnetic polarization at a magnetic field strength of 2500 A / m or 5000 A / m.
• P 1.5 is understood to mean the loss of remagnetization with a polarization of 1.5 T and a frequency of 50 Hz.
• the tape produced according to the known method has a special cube texture, a particularly high magnetic polarization of more than 1.7 T with a field strength J2500 of 2500 A / m and low magnetic reversal losses.
• this is Success tied to the specified, special composition. This applies in particular to the Mn content, for which it has surprisingly been found that it is necessary to set the desired cube texture.
• a certain ratio of the Si and Al contents has to be observed, through which the properties of the electrical sheet in question are decisively influenced. Since these requirements are not met for the entire range of products of interest here, the method described in EP 0 431 502 A2 is only suitable for the production of such sheets to which particularly high demands are made.
• the object of the invention is, based on the prior art summarized above, to provide a method with which a wide range of high-quality non-grain-oriented electrical sheets can be used improved magnetic properties.
• This object is achieved according to the invention by a method of the type specified at the outset, in the steel raw material, such as to a reheating temperature
• T HT [° C] 154-1.8 ⁇ t + 0.577 T ET + Hl d / d 0
• dn reference thickness of the hot strip in mm
• d actual thickness of the hot strip in mm t: time between the end of hot rolling and reeling in s
• ⁇ cooling factor in s "1 ,
• the cooling factors are preferably in the range of 1 s "1 ⁇ 0.3 s " 1 .
• the cooling can be done in air or with the support of Water.
• the reference thickness do is understood to be the thickness of a sample on which the respective cooling factor has been determined.
• An additional improvement in the results of the method according to the invention can be achieved in that, if the steel raw material is present as a pre-rolled slab, this slab is reheated to a temperature of up to 1250 ° C. in order to improve the precipitation structure.
• the reheating temperature with a maximum deviation of ⁇ 20 ° C should correspond to a reheating target temperature determined as follows:
• T ZBR target temperature of the reheated slab
• G S i Si content in mass%
• G A ⁇ Al content in mass%.
• the slab when using a slab as the starting material, it is advisable to pre-roll the slab in several passes to a thickness of 20-65 mm before the finish rolling. In this way, the degrees of deformation that can be achieved in the subsequent finish rolling to a strip thickness of ⁇ 3.5 mm are low, which promotes the development of excellent magnetic properties of the electrical sheet.
• the single-stitch decrease during the preliminary rolling of the slab is not more than 25%. This also favors the production of an electrical sheet with particularly good magnetic properties.
• a further improvement can be achieved in that the roughing is carried out in at least four passes. Through this measure, the emergence of a with regard to desired high magnetic polarization favorable structure additionally promoted.
• a further improvement in the results that can be achieved with the procedure according to the invention can be achieved in that the final rolling temperature during hot rolling with a maximum deviation of ⁇ 20 ° C. is not below a final rolling target temperature (T ZE ⁇ ) determined as follows:
• the finish rolling is carried out in several passes and the degrees of deformation decrease with increasing number of passes in the range from 50% to 5%.
• the invention makes it possible, by means of a specific coordination of the individual process steps, to produce improved electrical sheets with regard to their magnetic properties without the need for additional process steps which increase costs.
• electrical sheets can be produced in one process path which meet the increased demands placed on their magnetic properties.
• electrical sheets with optimized properties can also be produced based on special compositions.
• additional procedural steps Using a specially selected composition with the invention, produce electrical sheets which are highly flexible and as such meet even the strictest requirements.
• An essential aspect of the invention consists in the choice of the reel temperature which is to be set in accordance with the condition provided according to the invention for this purpose. If the reel temperature determined in this way is adhered to, a homogenization of the structure in the material which is matched to the respective final rolling temperature is achieved. This brings about an improvement in the properties of electrical sheets produced according to the invention with regard to the magnetic loss and the magnetic polarization.
• the rule given above is of particular importance for the dimensioning of the area of the finish rolling target temperature. If the finish rolling temperatures are chosen so that they fall within the range described by this rule, the reel temperature and finish rolling temperature are optimally matched to one another. This optimized coordination leads to a hot strip, on the basis of which the development of an advantageous magnetic texture is reinforced in the subsequent work steps.
• the magnetic polarization J2500 is plotted against the magnetic loss P 1.5 for different types of electrical sheet.
• the dash-dotted line A represents the magnetic properties of electrical sheets produced according to a conventional procedure, which are assigned to a first group A.
• EA6. • • •. E A9 . • • •. E On this line A each stand for the polarization of a specific electrical sheet of group A related to the magnetic reversal loss.
• Zone Z A5 encompasses the range of properties which an electrical sheet B ASE has, which was produced on the basis of the alloy L 5 also used for the production of the conventional sheet B ASH and which has undergone the method according to the invention.
• Zone Z A6 delimits the range of properties which an electrical sheet B A6 E has, which was produced on the basis of the alloy L ⁇ also used for the production of the conventional sheet B A6H and which also went through the process according to the invention.
• Zone Z A9 likewise encloses the range of properties which an electrical sheet B A9E has, which was produced on the basis of the alloy Lg also used for the production of the conventional sheet B A9H and which then went through the process according to the invention.
• zone Z A ⁇ o delimits the range of properties of an electrical sheet grade B AIOE assigned to group A and produced according to the invention, which has been produced on the basis of a low- silicon alloy L 10 .
• B AI0E compared to electrical sheets of the same group A, which have been produced on the basis of the same alloys but according to the conventional procedure, have improved magnetic properties.
• the magnetic polarization has been significantly increased. This makes it possible to follow the procedure according to the invention to produce electrical sheets whose magnetic polarization values are raised compared to conventionally produced electrical sheets of the same type, without the need for additional processing steps or changes in the alloy compositions.
• dashed line B represents the magnetic properties of electrical sheets, which are assigned to a second group B and have been processed in a conventional manner based on a material of a special composition.
• the specified high polarization values assume, in the conventional procedure, that the hot strip rolled from the relevant raw material is subjected to hot strip annealing.
• the corner points E B ⁇ , ..., E Bn in turn indicate the magnetic properties of an electrical sheet which has been produced in a conventional manner based on a particular alloy composition.
• a correspondingly composed steel raw material used to produce the electrical sheets assigned to this group B contains (in mass%) ⁇ 0.015% C, 0.1-1.1% Si, 0.05-0.3% Al, 0.08 - 0.5% Mn, ⁇ 0.02% S, 0.08 - 0.25% P, possibly further alloy additives as well as the lowest levels of usual accompanying elements and unavoidable impurities and the rest iron.
• the in the Diag. 1 entered zone Z B delimits the range of magnetic properties which arise in a correspondingly composed, low-siliconized electrical sheet after it has passed through the manufacturing process according to the invention. It should be emphasized that the electrical steel in question has not been subjected to hot strip annealing. Nevertheless, the specially composed tape produced in accordance with the invention has magnetic properties that are more conventional Procedure can only be achieved by using the cost-increasing hot strip annealing.
• Electrical sheets with further improved permeability can be produced if a steel raw material (in mass%) is used to produce them, which ⁇ 0.006% C, 0.15 - 0.5% Si, ⁇ 0.3% Al,> 0, 05 - 1.2%
• zone Z c in Diag.l corresponds to the magnetic properties that can be achieved if such a specially composed electrical sheet is produced in the manner according to the invention and is annealed as hot strip before cold rolling.
• Such an electrical sheet subjected to hot strip annealing in addition to the steps according to the invention during its production has magnetic properties which are far superior to conventionally produced electrical sheets even if these conventionally produced sheets have been subjected to hot strip annealing.
• an electrical sheet can be produced which, as in Diag. 1, has a magnetic polarization> 1.7 T with a magnetic field strength J2500 of 2500 A / m based on a magnetic loss P 1.5 of 4.5-5.5 W / kg and as such is superior to conventional metal sheets.
• the proportion of the further alloy additives which are, for example, P, Sn, Sb, Zr, V, Ti, N and / or B can act, limited to a maximum of 1.5%.
• a particularly preferred embodiment of the invention is characterized in that the annealing is carried out in the hood.
• the hot strip is advantageously kept at a maximum temperature of 650-850.degree. C. during the hood annealing for a holding time of 3 to 10 hours.
• Hot strip can be held for a holding time of ⁇ 1 minute at a maximum annealing temperature of 750 ° C to 1050 ° C.
• the outlay on equipment and the process times can be reduced by designing the continuous furnace as a combined annealing pickle.
• the final treatment carried out at the end of the method according to the invention comprises a final annealing in the continuous furnace.
• G A ⁇ Al content in mass%
• the holding time at the maximum final annealing temperature is ⁇ 30 seconds.
• the final treatment can include recrystallization annealing in a hood furnace or in a continuous furnace. If a bell-type furnace is used, it is advantageous if the maximum annealing temperature during the recrystallization annealing is between 580 ° C. and 780 ° C. and the holding time at the maximum annealing temperature lasts from 1 to 10 hours. It is also favorable if the recrystallization annealing is carried out under a pure gas, advantageously H 2 , or a non-decarburizing gas mixture. Alternatively, however, the recrystallization annealing can also be carried out in a decarburizing atmosphere formed by a gas mixture.
• the recrystallization annealing is carried out in a continuous furnace, it is advantageous if the cold strip is kept at a maximum annealing temperature of 750 ° C. to 1050 ° C. for a holding time of ⁇ 30 seconds.
• a maximum annealing temperature of 750 ° C. to 1050 ° C. for a holding time of ⁇ 30 seconds.
• Fig. 1 shows a flow chart of the manufacturing steps carried out in the production of electrical sheets of groups A and B.
• Fig. 2 the flowchart shows the steps which are carried out during the manufacture of electrical sheet grades assigned to group C.
• the slabs are then reheated to a reheating temperature T ZBR of up to 1250 ° C.
• the reheating temperature is determined with a maximum deviation of ⁇ 20 ° C in detail depending on the Si and Al content G S i, G A ⁇ of the respective alloy according to the equation
• the slab reheated in this way is pre-rolled in a number of passes, in which the single pass reduction is not more than 25%, to a thickness of 20-65 mm and introduced into a finishing mill with an inlet temperature T A ⁇ of a maximum of 1100 ° C. In this it becomes a hot strip with a thickness of ⁇ in several passes 3.5 mm rolled, the degrees of deformation decrease with increasing number of stitches in the range from 50% to 5%.
• the rolled hot strip is then coiled.
• the temperature T H ⁇ . with which the respective strips were coiled after hot rolling is calculated with a permissible deviation of at most 10 ° C according to the formula
• the reference thickness do of the hot strip was 3 mm in the examples, while the actual thickness d of the hot-rolled strip varied between 2.75 and 3.1 mm.
• the cooling factor ⁇ was in the range from 0.7 s "1 to 1.3 s " 1 .
• the time t between the end of hot rolling and the coiling was between 10 to 25 and 8 to 30 seconds, respectively.
• the final rolling temperature T E ⁇ that is present at the end of the finishing roll series and the respectively reached coiling temperature T H ⁇ are also given in Tables 1 and 2 for the individual examples.
• the hot strip passes through a pickling process without having been subjected to hot strip annealing and, after pickling, is cold-rolled in several passes to form a cold strip with a thickness of 0.2-1 mm with a total degree of deformation of maximum 85%.
• the strip is finally subjected to a final annealing in a continuous furnace as part of the last final treatment.
• the maximum temperature T SG reached in each case is also given in Tables 1 and 2.
• Tables 1 and 2 show the magnetic properties in addition to each individual example.
• Table 3 shows the corresponding information for examples of electrical sheets with the best magnetic properties assigned to group C. As can be seen from FIG. 2, these sheets pass through hot strip annealing as hot strip after pickling. If it is done continuously, this can be done in a combined annealing / pickling system.
• hot strip annealing was carried out as hood annealing.
• the holding times were 3 to 10 hours.
• the maximum temperatures T H G M a reached during the annealing are also shown in Table 3.
• the strip can be subjected to a recrystallization annealing treatment and then reshaped, the maximum degree of deformation being 15% (this alternative is indicated in FIGS. 1 and 2 by dash-dotted lines).

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Thermal Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Electromagnetism (AREA)
• Manufacturing Of Steel Electrode Plates (AREA)
• Soft Magnetic Materials (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Organic Insulating Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7905631

Family Applications (1)

Country Status (13)

Cited By (1)

Families Citing this family (22)

Family Cites Families (17)

• 1999
  • 1999-04-23 DE DE19918484A patent/DE19918484C2/de not_active Expired - Fee Related
• 2000
  • 2000-04-19 JP JP2000613837A patent/JP2002543274A/ja active Pending
  • 2000-04-19 ES ES00922652T patent/ES2200866T3/es not_active Expired - Lifetime
  • 2000-04-19 US US09/937,692 patent/US6582528B1/en not_active Expired - Lifetime
  • 2000-04-19 EP EP00922652A patent/EP1194600B1/fr not_active Expired - Lifetime
  • 2000-04-19 AU AU42969/00A patent/AU4296900A/en not_active Abandoned
  • 2000-04-19 PL PL00360057A patent/PL194747B1/pl unknown
  • 2000-04-19 BR BR0009990-2A patent/BR0009990A/pt not_active Application Discontinuation
  • 2000-04-19 MX MXPA01010684A patent/MXPA01010684A/es not_active Application Discontinuation
  • 2000-04-19 KR KR1020017013504A patent/KR100702242B1/ko active IP Right Grant
  • 2000-04-19 DE DE50002662T patent/DE50002662D1/de not_active Expired - Lifetime
  • 2000-04-19 AT AT00922652T patent/ATE243771T1/de active
  • 2000-04-19 CA CA002367602A patent/CA2367602A1/fr not_active Abandoned
  • 2000-04-19 WO PCT/EP2000/003558 patent/WO2000065103A2/fr active IP Right Grant
• 2009
  • 2009-02-27 JP JP2009045730A patent/JP2009185386A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events