EP0417318B1 - Procede pour produire une tole laminable a base de tole mince coulee solidifiee par trempe - Google Patents

Procede pour produire une tole laminable a base de tole mince coulee solidifiee par trempe Download PDF

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Publication number
EP0417318B1
EP0417318B1 EP90905626A EP90905626A EP0417318B1 EP 0417318 B1 EP0417318 B1 EP 0417318B1 EP 90905626 A EP90905626 A EP 90905626A EP 90905626 A EP90905626 A EP 90905626A EP 0417318 B1 EP0417318 B1 EP 0417318B1
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Prior art keywords
thin cast
cast sheet
sheet
annealing
process according
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German (de)
English (en)
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EP0417318A4 (en
EP0417318A1 (fr
Inventor
Kenzo Nippon Steel Corporation R&D Iwayama
Isao Nippon Steel Corporation R&D Iwayama
Kenichi Nippon Steel Corporation R&D Miyazawa
Toshiaki Nippon Steel Corporation R&D Mizoguchi
Hidehiko Nippon Steel Corporation Sumitomo
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Nippon Steel Corp
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Nippon Steel Corp
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Priority claimed from JP1079983A external-priority patent/JPH02258924A/ja
Priority claimed from JP1079982A external-priority patent/JPH02258920A/ja
Priority claimed from JP1079981A external-priority patent/JPH0323042A/ja
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP0417318A1 publication Critical patent/EP0417318A1/fr
Publication of EP0417318A4 publication Critical patent/EP0417318A4/en
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • 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
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
    • C21D7/06—Modifying the physical properties of iron or steel by deformation by cold working of the surface by shot-peening or the like
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon

Definitions

  • the present invention relates to a process for preparing a rollable metal sheet from a quench solidified thin cast sheet as a starting material capable of providing a good rolled shape when rollable metal sheets including various alloy sheets, such as soft iron, stainless steel, silicon steel, nickel-iron (permalloy), cobalt-iron (permendur), nickel, aluminum and copper sheets are prepared from a quench solidified thin cast slab or cast thin strip (hereinafter generally referred to as "thin cast sheet”) as a starting material.
  • various alloy sheets such as soft iron, stainless steel, silicon steel, nickel-iron (permalloy), cobalt-iron (permendur), nickel, aluminum and copper sheets are prepared from a quench solidified thin cast slab or cast thin strip (hereinafter generally referred to as "thin cast sheet") as a starting material.
  • various rollable metal sheets are produced by, for example, (i) a continuous casting to prepare a 200 mm-thick cast slab, (ii) heating the slab, (iii) hot rolling, (iv) annealing the hot rolled material, (v) cold rolling, and (vi) an optional heat treatment for working.
  • Recent demands for a reduction in production costs have led to proposals of various methods of eliminating the above-described steps (ii) and (iii) including the single roll and twin roll methods, which comprise continuously feeding a molten metal onto a cooling material having one or two cooling surfaces being transferred and renewed for quench solidification, thereby preparing a thin cast sheet having a thickness of several ten »m to about 10 mm.
  • the above-described single and twin roll methods, etc. provide a rollable metal with a high productivity at a low cost but are plagued by several fundamental problems, and therefore, currently the technology in this field is incomplete, although some products have been put to practical use.
  • the single or twin roll method is an excellent production method having not only the merit of a reduction of costs, such as an elimination of steps and the need for less plant and equipment investment, but also having an advantage in that a cold rolled material having a thickness as small as about several ten »m can be directly prepared.
  • the problem of the surface of the stainless steel sheet has hitherto been solved by conducting a mechanical descaling and pickling after annealing the hot rolled sheet, polishing the whole surface of the coil to remove various defects, and cold-rolling the coil with a large number of passes using a sendzimir mill comprising a multiple roll having a small diameter.
  • a process comprising the steps of annealing, pickling, surface polishing, and cold rolling by a small diameter roll is an established technique for preparing a thin strip of stainless steel having a fine surface, and 2D, 2B, and BA products specified in JIS have been produced thereby.
  • a similar method is disclosed in Japanese Unexamined Patent Publication No. 63-11619. This method is applied to a cast slab having a thickness of 0.7 to 2.0 mm.
  • All of the silicon steel sheets prepared by the above-described improved method exhibit a good mechanical property when the silicon content is high, but are unsatisfactory from the viewpoint of obtaining a high magnetic property, and stably reproducing these properties.
  • the process for preparing an unidirectional silicon steel sheet wherein use is made of a step of preparing a thin cast sheet by quench solidification is advantageous in that it is possible to eliminate the hot rolling step and increase the silicon content, but is unsatisfactory in the attaining of excellent properties and in the reproducibility of the conventional material subjected to the hot rolling. Further, a satisfactory cold rolling property is not attained in a high silicon content material.
  • An object of the present invention is to provide a method which solves the problem of the loss of the cold rolling property, which is a serious problem common to the production of a rollable metal sheet from a starting material comprising a quench solidified thin cast sheet prepared by the above-described single or twin roll method, i.e., to remarkably alleviate the fundamental difficulties encountered by the single or twin roll method when putting these methods to practical use.
  • An object of the present invention is to provide a novel method of improving the surface appearance of a thin cast sheet for general stainless steels, wherein the surface appearance is considered important in a cold rolled sheet or in the stage of final annealing, without a limitation to an austenitic stainless steel typically comprising 18% Cr-8% Ni or a ferritic stainless steel typically comprising 16.5% Cr.
  • another object of the present invention is to provide a process for stably preparing a unidirectional silicon steel having a low core loss, through a suitable regulation of the integrity and grain size of a ⁇ 110 ⁇ ⁇ 001> secondary recrystallized grain of a unidirectional silicon steel in a thin cast sheet form.
  • the present inventors made various studies with a view to solving the above-described problems of the prior art, and as a result, found that a particular working followed by a recrystallization of a fine grain in the worked region by annealing will suitably solve the above-described problems of the loss of the rolling property, etc., and thus completed the present invention.
  • the object of the present invention is to provide a process for preparing a metal sheet having an excellent rolling property, etc., i.e., a rollable metal sheet, which process comprises the basic steps of: continuously feeding a molten metal onto a cooling material having one or two cooling surfaces being transferred and renewed for quench solidification, to thereby prepare a thin cast sheet preferably having a thickness of 10 »m to about 6 mm; impinging small rigid body particles onto the surface of the resultant thin cast sheet, to work the cast sheet; heat-annealing the worked sheet in such a manner that the worked region becomes a fine recrystallized grain layer; and subjecting the sheet to a cold or warm rolling, optionally after a removal of oxides present on the surface; and an optional step of heat-treating the rolled sheet for working.
  • the cold rolling property with regard to the surface smoothness, sheet thickness controllability, and frequency of occurrence of problems such as a breaking of the metal sheet prepared by the prior art method is far inferior to that of a sheet subjected to hot rolling.
  • the cold rolling property and surface appearance can be remarkably improved through the introduction of the above-described step of working and the step of recrystallizing a fine grain in the worked region.
  • the secondary recrystallization can be remarkably stabilized, and the grain size made small, which makes it possible to prepare a unidirectional silicon steel sheet having a core loss of about 5% or more, which is superior to that of the conventional product.
  • the fine recrystallization at the surface portion of the cold rolling material steel sheet according to the present invention has the effect of not only improving the secondarily recrystallized grain but also remarkably improving the cold rolling property, so that according to the present invention, even a cast slab having a high silicon content and a thickness of up to 2.5 mm can be advantageously cold-rolled, compared to the known quench solidification method, for example, a method disclosed in Japanese Unexamined Patent Publication No. 63-11619, wherein the upper limit of the thickness of the cast slab is 2.0 mm.
  • a thin cast sheet prepared by the single or twin roll method i.e. by continuously feeding a molten metal onto a cooling material having one or two cooling surfaces being transferred and renewed for quench solidification, is used as a starting material.
  • the present invention can be advantageously applied to the production of various known rollable metal or alloy sheets, such as soft steel, stainless steel, silicon steel, nickel-iron, cobalt-iron, nickel, aluminium and copper sheets because, in these materials, the worked region can be finely crystallized through the steps of working and annealing, which are essential in the present invention, and the fine crystallization enables a remarkable improvement of the cold rolling property.
  • the reason why the thickness of the thin cast sheet is preferably limited to 10 »m to 6.0 mm is as follows.
  • the thickness exceeds 6.0 mm, the advantage of the elimination of the step is reduced and a relatively good rolling property can be obtained without the use of the present invention because, even when uneven portions exist, the proportion thereof in the whole sheet thickness is small.
  • the thickness must be 10 »m or more because there is substantially no need to use a starting material having a thickness of less than 10 »m, as rolling is conducted in the present invention as an indispensable step and it is almost impossible to prepare a thin cast sheet having a thickness of less than 10 »m.
  • the thickness is preferably 0.5 to 2.5 mm.
  • the thin cast sheet prepared by the quench solidification method is then worked by impinging small rigid body particles against the surface of the cast sheet. Specifically, a numerous number of particles of iron, sand or other material are impinged at a high speed against the surface of the thin cast sheet, for working; i.e., the thin cast sheet is subjected to blasting. "Grit" having an irregular shape and very sharp, or a shot having a relatively spherical shape, are used as the particles for the working.
  • the above-described working is applied to both surfaces, these surfaces including a side edge face or one surface depending upon the surface appearance, because a working of one surface causes warping.
  • the use of a large size shot not only increases the depth of the worked region but also increases the size of the impressions, and consequently, increases the surface roughness.
  • the size is preferably two times to a fraction of the thickness of the thin cast sheet.
  • the blasting time varies depending upon the type of metal, the unevenness of the thin cast sheet, and the purpose thereof, etc., but the working must be conducted in such a manner that substantially no unworked region exists and at least the surface of the sheet is covered with a fine recrystallized grain in the subsequent annealing.
  • the thin cast sheet thus worked is then heat-annealed.
  • the optimum temperature varies, depending upon the type of metal; for example, heating is preferably conducted at 650 to 1300°C for silicon-iron steel, stainless steel and nickel-iron, at 350 to 900°C for copper, and at 300 to 600°C for aluminum, for zero second to several hours.
  • the thin cast sheet wherein at least the surface thereof is covered with a fine recrystallized grain through the heat annealing is subjected to a step of removing an oxide, etc., present on the surface thereof according to need, and then to a series of steps including cold or warm rolling as a basic step depending upon the purpose, and then optionally, a heat treatment for working, to thereby prepare a final product.
  • the cold rolling property of the quench solidified thin cast sheet is improved by the present invention through the following mechanism.
  • the grit or shot blasting has the effect of smoothing uneven portions, particularly the boundary regions thereof present on the surface of the thin cast sheet, and the smoothing effect reduces "rippling", etc., during rolling.
  • the most important feature of the present invention is that the cold rolling is conducted in a state such that the surface of the thin cast sheet is covered with a fine recrystallized grain.
  • the present invention enables a metal sheet useful to the industry to be prepared from a quench solidified thin cast sheet.
  • the molten metal is a stainless steel and a unidirectional electrical sheet.
  • the stainless steel used in the present invention is formed of a stainless steel comprising known ingredients, and as described above, must be subjected to shot blasting and heat annealing (annealing for softening) before cold rolling.
  • FIG. 1 is a schematic explanatory view showing the process of the present invention.
  • a molten metal 2 in a tundish 1 is poured between cooling rolls 3 and is quench-solidified in a gap between the rolls 3 to form a thin cast sheet 4.
  • the surface of the thin cast sheet 4 is subjected to blasting by a shot blasting apparatus 5.
  • the worked sheet is annealed for softening by a heat annealing apparatus 6, scale is removed, and the sheet is cold rolled by a cold rolling mill 7.
  • Figure 2 (a), (b), and (c) are each a schematic view of a microphotograph wherein the sagging portion A of the thin cast sheet 4 shown in Fig. 1 is subjected to surface working and annealing.
  • a worked layer 8 is formed on the surface as shown in Fig. 2 (b) and the acute angle portion disappears.
  • a fine recrystallized grain layer 9 is formed as shown in Fig. 2 (c).
  • the above-described fine recrystallized grain 9 having an average diameter of 100 »m or less must be formed as a surface layer having a depth of 30 »m or more on the thin cast sheet.
  • Figure 3 shows the results of an observation of the surface appearance of metal sheets prepared by subjecting a 3 mm-thick thin cast slab of SUS 304 comprising a coarse crystal grain to shot blasting under various conditions, annealing the worked slab at 1100°C for various times, to vary the size of a fine crystallized grain and the depth of a surface layer, removing scale with aqua regia, and cold-rolling the slab at a draft of 70%.
  • the cold rolling causes a rough surface, e.g., "orange peel", to be formed due to the coarse crystal grain of the thin cast slab.
  • a rigid body particle such as shot or grit
  • shot or grit is projected onto the steel sheet before the annealing for softening, to thereby form a worked layer on the surface layer of the steel sheet.
  • a large number of particles of iron, sand or other material are impinged at a high speed onto the surface of the thin cast sheet, for working.
  • the blasting may be conducted under the same conditions as described above.
  • the thus blasted thin cast sheet is then annealed for softening.
  • heat annealing at a temperature of 700 to 1300°C for one sec to 10 min may be conducted, to recrystallize the grain to the above-described state.
  • the annealing temperature and time are lower than 700°C and shorter than 1 sec, respectively, no recrystallization occurs.
  • the annealing temperature and time are more than 1300°C and 10 min, respectively, this is not only cost-inefficient but also it becomes difficult to prepare a fine grain due to the growth of the crystal grain.
  • the surface defect of the cold-rolled sheet is alleviated through the following mechanism. Specifically, in the present embodiment, when the cold rolling is conducted in a state such that the surface of a thin cast sheet is covered with a fine recrystallized grain, the "drape" between the surface of the thin cast sheet and the surface of the rolling rolls becomes good, which causes the surface of the thin cast sheet to be actively polished, whereby a mirror surface is obtained. If the surface grains of the thin cast sheet are coarse, each crystal grain tends to have an external shape different from the surface of the rolls, due to the relationship with a slip system of the crystal grain. That is, it is believed that the formation of patterns different from particle to particle can be avoided because the "drape" with the surface of the rolling rolls becomes poor.
  • the steel composition is limited to 2.5 to 6.5% by weight of silicon, an inhibitor ingredient necessary for a grain oriented steel sheet, with the balance being iron and unavoidable impurities.
  • silicon content is less than 2.5%, a ⁇ phase is formed at a high temperature, which makes it unable to use a final annealing temperature of 1000°C or higher due to the growth of a secondary recrystallization, so that substantially no magnetic property can be secured.
  • the silicon content is limited to 2.5% or more.
  • the upper limit of the silicon content is set to 6.5% for the reason that, when the silicon content exceeds 6.5%, the cold rolling property becomes remarkably poor because the steel sheet becomes remarkably embrittled.
  • the effect of the present embodiment can be obtained in a grain oriented silicon steel sheet containing any known inhibitor ingredient.
  • the ingredients of the intended steel sheet may comprise 0.0005 to 0.10% of C, 0.02 to 0.35% of Mn, 0.0005 to 0.040% of sol. Al, 0.0005 to 0.04% of S, 0.0005 to 0.012% of N, 0.04% or less of Se, and 0.4% or less of at least one of Sn, Sb, As, Bi, Cu, Cr and Ni.
  • a molten metal having the above-described composition is then continuously fed onto a cooling material having one or two cooling surfaces being transferred and renewed for quench solidification, thereby preparing a thin cast sheet having a thickness of 0.5 to 2.5 mm.
  • the thickness exceeds 2.5 mm, the cooling rate becomes too low.
  • the thickness is less than 0.5 mm, it becomes difficult to conduct cold rolling with a final cold rolling draft of 80 to 98%.
  • the thickness is preferably 0.5 to 2.5 mm.
  • the thin cast sheet having a thickness of 0.5 to 2.5 mm prepared by the above-described casting method is cooled to 1000°C at a cooling rate of 102 to 104°C/sec. Thereafter, the thin cast sheet usually peels from the cooling material. In this case, it is preferred to spray water or warm water for cooling.
  • the thin cast sheet thus prepared is then subjected to an essential step of the present embodiment. Specifically, a small rigid body particle is impinged against the thin cast sheet, for working the surface portion.
  • a suitable size of the small rigid body particle varies depending upon the shape of the particle, impact speed, and incident angle, etc., but the particle size is preferably 0.2 to 2 times the thickness of the thin cast sheet.
  • the shape of the particle is preferably angular rather than spherical.
  • the surface of the thin cast sheet should be covered with impressions made by the impact of the small particles.
  • the thin cast sheet is annealed for recrystallization at 650 to 1300°C for 30 min or less.
  • the temperature is lower than 650°C, it is difficult to conduct recrystallization.
  • the temperature is higher than 1300°C, the inhibitor and structure become poor.
  • the heating time is longer than 30 min, the cost efficiency is lost. Therefore, the annealing time is limited as described above.
  • the heating temperature is low, the heating should be conducted for a long time, for example, at 700°C for 25 min, and when the heating temperature is high the heating should be conducted for a short time, for example, at 1250°C for 10 sec.
  • the thin cast sheet thus prepared is subjected to intermediate annealing, etc., according to need, repeatedly cold-rolled, and subjected to cold rolling as a final cold rolling at a draft of 80 to 98%.
  • the draft is less than 80%, the integrity of the secondarily recrystallized grain prepared after final annealing often becomes poor in the ⁇ 110 ⁇ ⁇ 001 ⁇ orientation.
  • the cold rolling draft is higher than 98%, it becomes difficult to ensure the secondary recrystallization.
  • the cold rolled sheet is then annealed at 600 to 1300°C at least once.
  • a secondary recrystallization can be attained even when the carbon content is e.g., 0.0030% or less.
  • annealing for the secondary recrystallization may be conducted only once at 900 to 1300°C.
  • carbon is contained in an amount of 0.0050% or more, it is preferred to conduct the decarburizing annealing at 750 to 900°C in a wet hydrogen gas stream, followed by the second annealing as a final annealing at 900 to 1300°C.
  • Goss nucleus One of the two mechanisms is the formation of a Goss nucleus, and the other is the homogenization of the primarily recrystallized matrix.
  • the secondarily recrystallized grains having a ⁇ 110 ⁇ ⁇ 001 ⁇ orientation of a grain oriented silicon steel sheet product are formed through the growth of a grain having a ⁇ 110 ⁇ ⁇ 001 ⁇ orientation among primarily recrystallized grains while eating out primarily recrystallized grains adjacent thereto.
  • a theory commonly accepted in the art through studies in recent years is that the origin of the "Goss nucleus" present in the primarily recrystallized grain structure exists as a Goss nucleus origin grain on the surface of the hot-rolled material.
  • the number of grains having an orientation suitable for the formation of the Goss nucleus is small and the grain having a ⁇ 100 ⁇ ⁇ ovw ⁇ orientation occupies the major portion of the grains. It is believed that a grain having an orientation corresponding to the Goss nucleus origin grain is introduced by subjecting the above-described thin cast sheet to working and recrystallization according to the present embodiment.
  • the other mechanism for improving the property is that, as with the present embodiment, the existence of a fine crystal grain on a grain of the surface limits the growth of grain in the central portion of the steel sheet, and consequently, homogenizes the primarily recrystallized matrix.
  • the homogenization of the primarily recrystallized matrix means a smooth growth of Goss nucleus having a good orientation, i.e., a ⁇ 110 ⁇ ⁇ 001 ⁇ orientation, and an improvement of the magnetic properties.
  • Permalloy PC comprising 76% nickel, 4.5% copper, and 4.5% molybdenum, with the balance being iron and unavoidable impurities, was vacuum melted, and a 0.30 mm thick thin cast sheet was prepared therefrom by a twin roll having a roll diameter of 300 mm.
  • the surface of the thin cast sheets had a recessed portion in a streak form and a sag.
  • the thin cast sheet was divided into two groups, i.e., groups A and B.
  • the sheets of group B were subjected to sand blasting by using sand having a particle diameter of 0.4 mm. Thereafter, the sheets of groups A and B were heat-annealed at 1100°C for 300 sec, descaled with aqua regia, and rolled to 0.10 mm by a cold rolling mill.
  • the above cold rolled materials were cut to a width of 1 cm, coated with MgO as an annealing releaser, wound in a toroidal form, maintained in a dry hydrogen gas stream at 1100°C for 3 hr, and subjected to furnace cooling at a cooling rate of 100°C/hr.
  • the magnetic properties of the materials were determined, and as a result, it was found that, as shown in Table 1, the scattering in the magnetic properties was large. It was found that the scattering was attributed to the scattering in the thickness of the cold sheet, and thus according to the present invention, not only is the cold rolling property improved but also variations in the magnetic properties can be prevented through the prevention of variations in the thickness of the cold rolled sheet.
  • Austenitic stainless steel (SUS 304) comprising 0.053% carbon, 18% chromium, and 8% nickel, with the balance being iron and unavoidable impurities, was vacuum-melted and a thin cast sheet having a thickness of 3.0 mm was prepared therefrom by a twin roll having a roll diameter of 400 mm.
  • the "sags" in a raindrop form having a height of 1 to 2 mm and a "ripple" were scattered over the surface of the thin cast iron.
  • the above-melted thin cast sheet was divided into two groups, i.e., groups A and B.
  • groups A and B a steel grit having a diameter of 0.8 mm was blasted by a compressed air stream directed onto the surface of the thin cast sheet for about 20 sec. This caused the whole surface of the thin cast sheet to be covered with a worked portion having an unevenness of 0.2 to 0.5 mm, and the average sheet thickness was 2.9 mm.
  • the worked thin cast sheets were subjected to heat annealing under various conditions of a heating temperature of 600 to 1200°C and a heating time of zero sec to 3 hr. At this stage, the section of the sheet was observed under a metallurgical microscope to confirm whether or not the surface was covered with a fine grain.
  • the thin cast sheet was divided into two groups, i.e., groups A and B. Both surfaces of the thin cast sheets of each group were scanned a number of times by the "air grit blasting machine" wherein small sand particles together with a high speed stream of compressed air were impinged against the steel sheet.
  • the sand particles had an average particle diameter of 0.8 mm.
  • the thin cast sheets thus scanned were heat-annealed at 1150°C for 2 min, subjected to a removal of scale formed during the annealing, with aqua regia, and then cold-rolled to a sheet thickness of 0.7 mm. After rolling oil was washed out, the cold rolled sheets were subjected to a final annealing at 1100°C for 60 sec, and the surface appearance was observed. Blasting conditions (number of times of scanning for varying the degree of working), the degree of fine recrystallization on the surface of the thin sheets in the heat annealing at 1150°C after blasting, and the results of observation of the surface appearance of the resultant cold-rolled sheets are shown in Table 3.
  • Thin cast sheets having a thickness of 2.5 mm (group A), 1.3 mm (group B) and 0.9 mm (group C) and comprising 0.06% carbon, 3.2% silicon, 0.71% manganese, 0.025% sulfur, 0.019% sol. aluminum, 0.008% nitrogen, and 0.15% tin, with the balance consisting essentially of iron, were prepared by a method wherein a molten metal was poured into a gap between rotated metallic twin rolls having a diameter of 300 mm, while cooling the resultant sheet with water at the outlet of the twin roll. Both surfaces of these thin cast sheets were scanned a number of times by the "air grit blasting machine" wherein small sand particles together with a high speed stream of compressed air was impinged against the steel sheet.
  • the average particle diameter of the sand was 1 mm for group A, 0.7 mm for group B and 0.5 mm for group C.
  • the thus scanned steel sheets were annealed at 1100°C for 2 min, and pickled and cold-rolled to a final sheet thickness at a draft of 86%.
  • the steel sheets were subjected to decarburizing annealing in a wet hydrogen gas stream, coated with MgO as an annealing releaser, and subjected to secondary recrystallization ⁇ purification annealing at 1180°C for 15 hr in a dry hydrogen gas stream.
  • the blasting conditions (number of times of scanning for varying the degree of working), the degree of fine recrystallization on the surface of the steel sheets after the annealing at 1100°C after blasting, and the final magnetic properties are shown in Table 4.
  • rollable metal sheets prepared from a quench solidified thin cast sheet according to the present invention have a far better cold rolling property than metal sheets prepared from the conventional quench solidified thin cast sheet.
  • the products prepared according to the process of the present invention have a superior surface appearance compared to the products prepared by the conventional process.
  • the products according to the present invention have superior magnetic properties.
  • the present invention increases the practicability of the process wherein a step of hot rolling has been eliminated, which renders the present invention very useful to industry from the viewpoints of energy saving, and less plant and equipment investment.

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  • Continuous Casting (AREA)
  • Metal Rolling (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Laminated Bodies (AREA)

Abstract

Un procédé pour produire une tôle dite 'laminable' présentant une aptitude élevée au laminage, consiste essentiellement à acheminer en continu du métal en fusion à un élément de refroidissement dont la surface de refroidissement comporte une ou deux surfaces qui sont animées d'un mouvement et renouvelées, puis à tremper et à solidifier ledit métal pour obtenir une tôle mince coulée, à provoquer le choc de petites particules rigides contre la surface de ladite tôle pour travailler, chauffer et recuire celle-ci afin que la zone travaillée devienne une couche recrystallisée à grains très fins, puis à effectuer un laminage à froid ou à chaud après élimination des oxydes de surface ou de ce genre, s'il y a lieu, et à réaliser un traitement thermo-mécanique le cas échéant. Ce procédé s'applique à la production de diverses tôles de métal ou d'alliage laminables tels que les tôles d'acier doux connues, les tôles en acier inoxydable, les tôles en acier siliconé, les tôles Ni-Fe, les tôles Co-Fe, les tôles Ni, les tôles en Al, et les tôles en Cu.

Claims (14)

  1. Procédé de production d'une tôle métallique laminable à partir d'une tôle mince coulée solidifiée par trempage comme produit de départ, qui comprend une étape consistant à introduire en continu un métal fondu sur une matière de refroidissement ayant une ou deux surfaces de refroidissement transférée et renouvelée pour solidification de la trempe, afin de préparer ainsi une tôle mince coulée; une étape consistant à frapper avec de petites particules de corps rigide la surface de la tôle mince coulée, pour usiner la tôle coulée; une étape consistant à effectuer un recuit thermique de la tôle usinée de manière que la région usinée devienne une couche à grains fins recristallisés; et une étape consistant à soumettre la tôle à un laminage à froid ou à chaud.
  2. Procédé selon la revendication 1 dans lequel la tôle mince coulée a une épaisseur de 10 »m à 6,0 mm.
  3. Procédé selon la revendication 1 ou 2, dans lequel on enlève l'oxyde présent à la surface de la tôle mince coulée après l'étape de recuit thermique.
  4. Procédé selon la revendication 1, 2 ou 3, dans lequel on effectue un traitement thermique pour usinage après l'étape de laminage à froid ou à chaud.
  5. Procédé selon la revendication 1, dans lequel le métal fondu est un acier inoxydable.
  6. Procédé selon la revendication 5, dans lequel on projette de petits corps rigides comprenant de la mitraille ou de la grenaille à la surface de la tôle mince coulée d'acier inoxydable, pour former une couche usinée à la surface de la tôle mince coulée, on effectue un recuit thermique de la tôle mince coulée entre 700 et 1300°C pendant 1 seconde à 10 minutes pour former une couche comprenant des grains fins recristallisés ayant un diamètre moyen égal ou inférieur à 100 »m dans la couche superficielle résultante ayant une profondeur égale ou supérieure à 30 »m sur la tôle mince coulée, et on soumet la tôle mince coulée à un laminage à froid et à un recuit final pour préparer une tôle d'acier inoxydable ayant l'aspect superficiel requis.
  7. Procédé selon la revendication 1, dans lequel le métal fondu comprend de 2,5 à 6,5% en poids de silicium et un ingrédient inhibiteur nécessaire à une tôle d'acier au silicium à grains orientés, le reste étant constitué de fer et d'impuretés inévitables.
  8. Procédé selon la revendication 7, qui comprend une étape consistant à solidifier par trempage en continu le métal fondu pour préparer une tôle mince coulée ayant une épaisseur de 0,5 à 2,5 mm; frapper avec de petites particules de corps rigide la tôle mince coulée résultante, pour former une couche usinée à sa surface; effectuer un recuit thermique de la tôle mince coulée entre 650 et 1300°C pendant 30 minutes ou moins pour former une coucha mince recristallisée dans la région de la couche superficielle usinée par collision; et soumettre la tôle mince coulée à un laminage à froid final à un retrait de 50 à 98% et au moins un recuit à une température de 600 à 1300°C.
  9. Procédé selon la revendication 8, dans lequel on soumet la tôle mince coulée à un laminage et à un recuit intermédiaire avant le laminage à froid final.
  10. Procédé selon la revendication 1, dans lequel le métal fondu est un alliage nickel-fer, un alliage cobalt-fer, du nickel métal, de l'aluminium métal et du cuivre métal.
  11. Procédé selon la revendication 10, qui comprend une étape consistant à solidifier par trempage en continu le métal fondu pour préparer une mince tôle coulée ayant une épaisseur de 10 »m à 6,0 mm; frapper avec de petites particules de corps rigide la mince tôle coulée résultante, pour former une couche usinée à sa surface; effectuer un recuit thermique de la mince tôle coulée pour former une couche fine recristallisée dans la région de la couche superficielle usinée par collision; et soumettre la tôle mince coulée à un laminage à froid ou à chaud.
  12. Procédé selon la revendication 11, dans lequel on effectue un recuit à chaud de la mince tôle coulée comprenant un alliage nickel-fer à une température de 650 à 1300°C.
  13. Procédé selon la revendication 11, dans lequel on effectue un recuit à chaud de la mince tôle coulée comprenant de l'aluminium à une température de 300 à 600°C.
  14. Procédé selon la revendication 11, dans lequel on effectue un recuit à chaud de la mince tôle coulée comprenant du cuivre à une température de 350° à 900°C.
EP90905626A 1989-03-30 1990-03-30 Procede pour produire une tole laminable a base de tole mince coulee solidifiee par trempe Expired - Lifetime EP0417318B1 (fr)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP1079983A JPH02258924A (ja) 1989-03-30 1989-03-30 一方向性珪素鋼板の製造方法
JP1079982A JPH02258920A (ja) 1989-03-30 1989-03-30 表面性状の優れたステンレス鋼薄帯の製造方法
JP79981/89 1989-03-30
JP79982/89 1989-03-30
JP79983/89 1989-03-30
JP1079981A JPH0323042A (ja) 1989-03-30 1989-03-30 急冷凝固薄鋳板を素材とする圧延性金属板の製造方法
PCT/JP1990/000442 WO1990011849A1 (fr) 1989-03-30 1990-03-30 Procede pour produire une tole laminable a base de tole mince coulee solidifiee par trempe

Publications (3)

Publication Number Publication Date
EP0417318A1 EP0417318A1 (fr) 1991-03-20
EP0417318A4 EP0417318A4 (en) 1992-08-26
EP0417318B1 true EP0417318B1 (fr) 1995-06-07

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EP90905626A Expired - Lifetime EP0417318B1 (fr) 1989-03-30 1990-03-30 Procede pour produire une tole laminable a base de tole mince coulee solidifiee par trempe

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EP (1) EP0417318B1 (fr)
KR (1) KR940003251B1 (fr)
CA (1) CA2030538C (fr)
DE (1) DE69019895T2 (fr)
ES (1) ES2073022T3 (fr)
WO (1) WO1990011849A1 (fr)

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DE19745445C1 (de) * 1997-10-15 1999-07-08 Thyssenkrupp Stahl Ag Verfahren zur Herstellung von kornorientiertem Elektroblech mit geringem Ummagnetisierungsverlust und hoher Polarisation

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JPH0737652B2 (ja) * 1990-03-30 1995-04-26 新日本製鐵株式会社 Ｆｅ―Ｎｉ系高透磁率磁性合金の製造方法
CA2141775A1 (fr) * 1994-09-02 1996-03-03 Murray W. Mahoney Procede pour introduire une microstructure ponctuelle a granulometrie fine sur des surfaces selectionnees d'alliages d'aluminium
DE59800478D1 (de) * 1998-10-01 2001-03-22 Lamitref Ind N V Copper cathode starting sheets for copper electrolysis and manufacture thereof
AU2008100847A4 (en) 2007-10-12 2008-10-09 Bluescope Steel Limited Method of forming textured casting rolls with diamond engraving
CN102764761B (zh) * 2012-07-26 2015-02-25 武汉钢铁(集团)公司 难加工材料近终成形制造方法
CN109822070B (zh) * 2018-12-28 2020-12-01 日照钢铁控股集团有限公司 一种薄板坯全无头轧制电驱动用无取向电工钢及制备方法
CN114769593A (zh) * 2022-06-02 2022-07-22 安泰科技股份有限公司 一种制备钼及钼合金箔材的方法

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JPS6056020A (ja) * 1983-09-06 1985-04-01 Kawasaki Steel Corp （１００）面内無方向性けい素鋼薄帯の製造方法
JPS6167720A (ja) * 1984-09-07 1986-04-07 Nippon Steel Corp 珪素鋼熱延板の焼鈍方法
JPS61195919A (ja) * 1985-02-27 1986-08-30 Nippon Steel Corp 耐ストレツチヤ・ストレイン性の優れた冷延鋼板の製造方法
JPS62197247A (ja) * 1986-02-21 1987-08-31 Nippon Yakin Kogyo Co Ltd 異方性が小さくかつ結晶粒が粗大化し難いオーステナイト系ステンレス鋼薄板帯の製造方法
JPS6383224A (ja) * 1986-09-26 1988-04-13 Nippon Steel Corp Ｃｒ系ステンレス鋼薄板の製造方法
US4799974A (en) * 1987-05-27 1989-01-24 Rockwell International Corporation Method of forming a fine grain structure on the surface of an aluminum alloy
JPS6372824A (ja) * 1987-07-28 1988-04-02 Kawasaki Steel Corp 高けい素鋼急冷薄帯の磁気特性を改善する圧延処理方法

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19745445C1 (de) * 1997-10-15 1999-07-08 Thyssenkrupp Stahl Ag Verfahren zur Herstellung von kornorientiertem Elektroblech mit geringem Ummagnetisierungsverlust und hoher Polarisation

Also Published As

Publication number Publication date
KR940003251B1 (ko) 1994-04-16
DE69019895T2 (de) 1996-02-22
ES2073022T3 (es) 1995-08-01
CA2030538C (fr) 1996-04-23
DE69019895D1 (de) 1995-07-13
WO1990011849A1 (fr) 1990-10-18
CA2030538A1 (fr) 1990-10-01
EP0417318A4 (en) 1992-08-26
KR920700077A (ko) 1992-02-19
EP0417318A1 (fr) 1991-03-20

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