EP0681031A1 - Process for manufacturing mild steel - Google Patents
Process for manufacturing mild steel Download PDFInfo
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- EP0681031A1 EP0681031A1 EP95200245A EP95200245A EP0681031A1 EP 0681031 A1 EP0681031 A1 EP 0681031A1 EP 95200245 A EP95200245 A EP 95200245A EP 95200245 A EP95200245 A EP 95200245A EP 0681031 A1 EP0681031 A1 EP 0681031A1
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- Prior art keywords
- steel
- process according
- annealing
- rolling
- strip
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- 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
- C21D8/1227—Warm rolling
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- 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
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- 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
Definitions
- the present invention relates to a method for manufacturing mild steel, in particular mild steel with a low coercive field for the manufacture of magnets used in particle accelerators or similar installations, such as a storage ring, etc. .
- particle accelerators of a certain size require magnets from a steel with a very specific set of characteristics.
- this steel has sufficient mechanical strength and specific magnetic properties, such as a relatively low coercive field with a slightly dispersed average value, an absence of aging of the magnetic properties, a magnetic permeability guaranteeing high levels of induction as well as a very low level of magnetic loss making it possible to work with sheet thicknesses equal to or greater than 1.5 mm.
- the flatness of the constituent parts of the magnet must be such as to ensure a high filling coefficient, preferably greater than 98%.
- These parts must also have very tight thickness tolerances, have no mechanical tension, be practically free of carbon, resist corrosion, be able to be machined and cut easily, and finally be able to be as thick as possible.
- the invention aims to present an economically justified process for the treatment of a steel with a view to obtaining a mild steel meeting as much as possible the criteria defined above.
- This process is characterized by the fact that one starts from a steel corresponding to the following composition: C ⁇ 1% If ⁇ 1% Mn ⁇ 1% P ⁇ 0.100% S ⁇ 0.100% N ⁇ 0.100% Al ⁇ 0.250%, that slabs are formed from such steel, that these slabs are subjected to a rolling process conducted at least in part in the ferritic phase until a strip with a thickness of 1 to 12 mm is obtained and that this steel strip undergoes self-annealing and / or is subjected to a controlled annealing, so as to obtain crystallization of the rolled steel in the ferritic phase.
- the slabs thus obtained are reheated in order to increase the malleability of the steel and thus facilitate subsequent rolling.
- This reheating is carried out for example at a temperature of 900 to 1250 ° C.
- This rolling is carried out until a steel strip with a thickness of 1 to 12 mm is obtained, depending on the application envisaged.
- This steel strip thus obtained undergoes self-annealing and / or is subjected to a controlled annealing so as to obtain a crystallization identical to that of rolled steel in the ferritic phase.
- the steel coil is introduced into an oven for a determined time and is brought to a temperature which is in particular a function of this residence time in the oven.
- controlled annealing is carried out at a temperature between 400 and 910 ° C. for a period of 3 minutes to 48 hours and preferably from 30 minutes to 48 hours, while ensuring that the periods of stay in the oven shorter correspond to the highest annealing temperatures and conversely that the longest times correspond to the lowest temperatures.
- This pickling preferably takes place before annealing.
- pickling and annealing can, if necessary, be carried out simultaneously, for example in a reducing atmosphere rich in hydrogen.
- advantageously cylinders are used. rolling lubricated thereby reducing the friction effect on the surface of slabs and steel strips during rolling.
- the slabs obtained were subjected to reheating for 1 hour 30 minutes at a temperature of 1250 ° C.
- the thickness of the steel strip obtained was 2.5 mm. Then took place the winding of the steel strip at an average temperature of about 680 ° C and therefore it undergoes self-annealing. Finally, a conventional chemical pickling was applied to the steel strip after having laid it flat and cut into sheets.
- the grain size in the finished strip was 5 ASTM and the coercive field was 95 A / m.
- the slabs formed from such a steel were subjected to reheating at a temperature of 1250 ° C. for approximately 1 hour and a half.
- the rolling was carried out on a continuous finishing train. At the entry of the latter the temperature of the steel was of the order of 900 ° C. and at the exit of the order of 750 ° C. The strip was then wound at a temperature of 750 ° C. Subsequently, a cold rolling finish, namely a skin pass of 2%, was carried out. After a conventional chemical pickling in a sulfuric medium, continuous annealing was carried out at a temperature of 825 ° C. and this for a period of 90 seconds. Then finally the strip was subjected to a "HOWAQ" quenching at 400 ° C. and to monitoring for 200 seconds at 400 ° C. followed by a further etching with formic acid and a new skin pass of 0, 2%.
- a cold rolling finish namely a skin pass of 2%
- the grain size in the finished steel strip was 2 ASTM and the coercive field was 80 A / m.
- the reheat temperature was 1050 ° C for 2 hours.
- the average temperature at the paver was 840 ° C.
- the winding temperature was 730 ° C.
- This sheet then presented a coercive field of 50 A / m and an induction of 1.95 Ts at a magnetic field of 100 A / cm.
- the reheat temperature was 1000 ° C for 2 hours 15 minutes.
- the inlet temperature of the paver was 900 ° C and the outlet temperature of 675 ° C.
- the winding temperature was 200 ° C and the thickness of the strip leaving the finisher was 0.8 mm.
- the steel obtained had an ASTM 1 grain and a coercive field of 40 A / m.
- the induction was 0.8 Ts at a magnetic field of 40 A / m.
- the reheating temperature was 1250 ° C for 1 hour 30 minutes.
- the average temperature in the paver was 760 ° C.
- the winding temperature was 300 ° C and this was followed by chemical pickling.
- Annealing was carried out in a hydrogen medium at a temperature of 750 ° C.
- the steel obtained had an ASTM grain of 5-6.
- the coercive field was 110 A / m.
- a calamine removal treatment can, if necessary, take place at different stages of the process.
- This treatment can be a chemical pickling or a mechanical descaling such as, respectively, a reduction of the metal oxide by a reducing agent, such as for example hydrogen, or a shot peening.
- the rolled steel strip can be kept at a substantially uniform temperature relatively low at most 150 ° C before its possible winding.
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- Engineering & Computer Science (AREA)
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- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Electromagnetism (AREA)
- Metallurgy (AREA)
- Thermal Sciences (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Lubricants (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Metal Extraction Processes (AREA)
- Manufacturing Of Steel Electrode Plates (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
La présente invention est relative à un procédé de fabrication d'acier doux, notamment d'un acier doux à bas champ coercitif pour la fabrication d'aimants utilisés dans les accélérateurs de particules ou installations analogues, tel qu'un anneau de stockage, etc.The present invention relates to a method for manufacturing mild steel, in particular mild steel with a low coercive field for the manufacture of magnets used in particle accelerators or similar installations, such as a storage ring, etc. .
D'une façon générale, les accélérateurs de particules d'une certaine dimension nécessitent des aimants d'un acier présentant un ensemble de caractéristiques bien spécifiques. Ainsi, il faut tout d'abord que cet acier présente une résistance mécanique suffisante et des propriétés magnétiques particulières, tel qu'un champ coercitif relativement bas avec une valeur moyenne faiblement dispersée, une absence de vieillissement des propriétés magnétiques, une perméabilité magnétique garantissant de hauts niveaux d'induction ainsi qu'un niveau de perte magnétique très bas permettant de travailler à des épaisseurs de tôles égales ou supérieures à 1,5 mm.Generally speaking, particle accelerators of a certain size require magnets from a steel with a very specific set of characteristics. Thus, it is first of all necessary that this steel has sufficient mechanical strength and specific magnetic properties, such as a relatively low coercive field with a slightly dispersed average value, an absence of aging of the magnetic properties, a magnetic permeability guaranteeing high levels of induction as well as a very low level of magnetic loss making it possible to work with sheet thicknesses equal to or greater than 1.5 mm.
De plus, la planéité des pièces constitutives de l'aimant doit être telle qu'elle permette d'assurer un coefficient de remplissage élevé, de préférence supérieur à 98 %. Ces pièces doivent également présenter des tolérances d'épaisseurs très serrées, ne présenter aucune tension mécanique, être pratiquement exemptes de carbone, résister à la corrosion, pouvoir être usinées et découpées facilement et enfin pouvoir se présenter en des épaisseurs aussi élevées que possible.In addition, the flatness of the constituent parts of the magnet must be such as to ensure a high filling coefficient, preferably greater than 98%. These parts must also have very tight thickness tolerances, have no mechanical tension, be practically free of carbon, resist corrosion, be able to be machined and cut easily, and finally be able to be as thick as possible.
L'invention vise à présenter un procédé économiquement justifié pour le traitement d'un acier en vue d'obtenir un acier doux répondant autant que possible aux critères définis ci-dessus.The invention aims to present an economically justified process for the treatment of a steel with a view to obtaining a mild steel meeting as much as possible the criteria defined above.
Ce procédé est caractérisé par le fait que l'on part d'un acier répondant à la composition suivante :
C ≦ 1 %
Si ≦ 1 %
Mn < 1 %
P < 0,100 %
S < 0,100 %
N < 0,100 %
Al ≦ 0,250 %,
que l'on forme des brames à partir d'un tel acier, que l'on soumet ces brames à un laminage conduit au moins en partie dans la phase ferritique jusqu'à obtenir une bande d'une épaisseur de 1 à 12 mm et que cette bande d'acier subit un auto-recuit et/ou est soumise un recuit contrôlé, de manière à obtenir une cristallisation de l'acier laminé dans la phase ferritique.This process is characterized by the fact that one starts from a steel corresponding to the following composition:
C ≦ 1%
If ≦ 1%
Mn <1%
P <0.100%
S <0.100%
N <0.100%
Al ≦ 0.250%,
that slabs are formed from such steel, that these slabs are subjected to a rolling process conducted at least in part in the ferritic phase until a strip with a thickness of 1 to 12 mm is obtained and that this steel strip undergoes self-annealing and / or is subjected to a controlled annealing, so as to obtain crystallization of the rolled steel in the ferritic phase.
Avantageusement, on part d'un acier répondant à la composition suivante :
C ≦ 0,010 %
Si ≦ 0,30 %
Mn < 1 %
P < 0,030 %
S < 0,020 %
N < 0,010 %
Al < 0,100 %,
les brames formées à partir d'un tel acier étant soumises à un laminage dans la phase ferritique à une température de 200 à 900°C avant le recuit précité.Advantageously, we start from a steel corresponding to the following composition:
C ≦ 0.010%
If ≦ 0.30%
Mn <1%
P <0.030%
S <0.020%
N <0.010%
Al <0.100%,
the slabs formed from such a steel being subjected to rolling in the ferritic phase at a temperature of 200 to 900 ° C before the aforementioned annealing.
D'autres détails et particularités de l'invention ressortiront de la description donnée ci-après, à titre non-limitatif, de quelques formes de réalisation du procédé de l'invention illustré par les exemples concrets d'application.Other details and particularities of the invention will emerge from the description given below, without limitation, of some forms of carrying out the method of the invention illustrated by concrete examples of application.
D'une façon générale, en fonction des paramètres des étapes successives du procédé de l'invention, on part d'un acier répondant à la composition générale suivante :
C ≦ 1 %
Si ≦ 1 %
Mn < 1 %
P < 0,100 %
S < 0,100 %
N < 0,100 %
Al ≦ 0,250 %.
A partir de cet acier, on coule des brames, par exemple d'une épaisseur de 200 à 300 mm. A noter qu'une décarburation de l'acier liquide peut avantageusement être réalisée. Cette décarburation peut être favorisée par l'addition à l'acier à l'état fondu d'éléments carburigènes notamment Nb, Ti, V, de préférence à des concentrations qui sont telles que le carbone libre dans les brames coulées soit inférieur à 0,006 %.In general, depending on the parameters of the successive stages of the process of the invention, one starts from a steel corresponding to the following general composition:
C ≦ 1%
If ≦ 1%
Mn <1%
P <0.100%
S <0.100%
N <0.100%
Al ≦ 0.250%.
From this steel, slabs are poured, for example with a thickness of 200 to 300 mm. Note that decarburization of liquid steel can advantageously be carried out. This decarburization can be favored by the addition to the molten steel of carburogenic elements, in particular Nb, Ti, V, preferably at concentrations which are such that the free carbon in the cast slabs is less than 0.006%. .
Le cas échéant, les brames ainsi obtenues sont réchauffées dans le but d'augmenter la malléabilité de l'acier et ainsi d'en faciliter le laminage ultérieur. On réalise ce réchauffage par exemple à une température de 900 à 1250°C.Where appropriate, the slabs thus obtained are reheated in order to increase the malleability of the steel and thus facilitate subsequent rolling. This reheating is carried out for example at a temperature of 900 to 1250 ° C.
Ensuite, après dégrossissage de ces brames sur un train classique, on procède alors à un laminage dans la phase ferritique.Then, after roughing these slabs on a conventional train, rolling is then carried out in the ferritic phase.
Ainsi, pour assurer qu'au moins la fin de ce laminage aura réellement lieu dans cette phase ferritique, celui-ci aura avantageusement lieu à une température inférieure à 900°C.Thus, to ensure that at least the end of this rolling will actually take place in this ferritic phase, it will advantageously take place at a temperature below 900 ° C.
Ceci permet d'obtenir un produit non-cristallisé écroui, se présentant quelque peu sous forme de fibres très dures.This makes it possible to obtain a hardened non-crystallized product, which is somewhat in the form of very hard fibers.
On réalise ce laminage jusqu'à obtenir une bande d'acier d'une épaisseur de 1 à 12 mm, suivant l'application envisagée.This rolling is carried out until a steel strip with a thickness of 1 to 12 mm is obtained, depending on the application envisaged.
Cette bande d'acier ainsi obtenue subit un auto-recuit et/ou est soumise à un recuit contrôlé de manière à obtenir une cristallisation identique à celle de l'acier laminé dans la phase ferritique.This steel strip thus obtained undergoes self-annealing and / or is subjected to a controlled annealing so as to obtain a crystallization identical to that of rolled steel in the ferritic phase.
L'auto-recuit qui se produit automatiquement, suite à la température à laquelle se trouve la bande, a lieu pendant et après le bobinage de ces bandes d'acier laminées.The self-annealing which occurs automatically, following the temperature at which the strip is found, takes place during and after the winding of these rolled steel strips.
Par contre, au cas où un recuit contrôlé est désiré, la bobine d'acier est introduite dans un four pendant un temps déterminé et est portée à une température qui est notamment fonction de ce temps de séjour dans le four.On the other hand, if a controlled annealing is desired, the steel coil is introduced into an oven for a determined time and is brought to a temperature which is in particular a function of this residence time in the oven.
Ainsi, on effectue par exemple le recuit contrôlé à une température comprise entre 400 et 910°C pendant une durée de 3 minutes à 48 heures et de préférence de 30 minutes à 48 heures, ce en veillant que les durées de séjour dans le four les plus courtes correspondent aux températures de recuit les plus élevées et inversement que les durées les plus longues correspondent aux températures les plus basses.Thus, for example, controlled annealing is carried out at a temperature between 400 and 910 ° C. for a period of 3 minutes to 48 hours and preferably from 30 minutes to 48 hours, while ensuring that the periods of stay in the oven shorter correspond to the highest annealing temperatures and conversely that the longest times correspond to the lowest temperatures.
De plus, suivant l'invention, on peut prévoir également une étape de décapage de la bande d'acier ainsi laminée.In addition, according to the invention, it is also possible to provide a step of pickling the steel strip thus rolled.
Ce décapage a de préférence lieu avant le recuit. Toutefois, le décapage et le recuit peuvent, le cas échéant, être effectués simultanément, par exemple dans une atmosphère réductrice riche en hydrogène.This pickling preferably takes place before annealing. However, pickling and annealing can, if necessary, be carried out simultaneously, for example in a reducing atmosphere rich in hydrogen.
Par ailleurs, dans le but d'obtenir une structure cristallographique sensiblement homogène dans toute la section de la bande laminée, surtout dans la zone de surface par rapport à la zone centrale de la bande, on utilise avantageusement des cylindres de laminage lubrifiés réduisant ainsi l'effet de frottement à la surface des brames et des bandes d'acier lors du laminage.Furthermore, in order to obtain a substantially homogeneous crystallographic structure throughout the section of the laminated strip, especially in the surface area relative to the central area of the strip, advantageously cylinders are used. rolling lubricated thereby reducing the friction effect on the surface of slabs and steel strips during rolling.
Ci-après sont donnés quelques exemples concrets de réalisation du procédé suivant l'invention à partir d'un acier d'une composition bien déterminée.Below are given some concrete examples of carrying out the process according to the invention from a steel of a well-defined composition.
L'acier utilisé pour la formation des brames présentait la composition suivante :
C = 0,002 %
Mn = 0,110 %
S = 0,004 %
Si = 0,005 %
P = 0,012 %
Al = 0,012 %
N = 0,0015 %
Les brames obtenues ont été soumises à un réchauffage pendant 1 heures 30 minutes à une température de 1250°C.The steel used for slab formation had the following composition:
C = 0.002%
Mn = 0.110%
S = 0.004%
If = 0.005%
P = 0.012%
Al = 0.012%
N = 0.0015%
The slabs obtained were subjected to reheating for 1 hour 30 minutes at a temperature of 1250 ° C.
Ensuite a eu lieu le laminage à une température qui était de 900°C à l'entrée et de 780°C à la sortie du finisseur.Then the rolling took place at a temperature which was 900 ° C at the inlet and 780 ° C at the outlet of the finisher.
L'épaisseur de la bande d'acier obtenu était de 2,5 mm. Ensuite a eu lieu le bobinage de la bande d'acier à une température moyenne de l'ordre de 680°C et de ce fait elle subit un auto-recuit. Enfin, un décapage chimique classique a été appliqué sur la bande d'acier après l'avoir mise à plat et découpée en feuilles.The thickness of the steel strip obtained was 2.5 mm. Then took place the winding of the steel strip at an average temperature of about 680 ° C and therefore it undergoes self-annealing. Finally, a conventional chemical pickling was applied to the steel strip after having laid it flat and cut into sheets.
La taille du grain dans la bande terminée était de 5 ASTM et le champs coercitif était égal à 95 A/m.The grain size in the finished strip was 5 ASTM and the coercive field was 95 A / m.
L'acier utilisé présentait la composition suivante :
C = 0,005 %
Mn = 0,250 %
Ti = 0,040 %
Al = 0,005 %
Si = 0,200 %
S = 0,008 %
P = 0,013 %.The steel used had the following composition:
C = 0.005%
Mn = 0.250%
Ti = 0.040%
Al = 0.005%
If = 0.200%
S = 0.008%
P = 0.013%.
Comme dans l'exemple précédent, les brames formés à partir d'un tel acier ont été soumises à un réchauffage à une température de 1250°C pendant environ 1 heure et demie.As in the previous example, the slabs formed from such a steel were subjected to reheating at a temperature of 1250 ° C. for approximately 1 hour and a half.
Le laminage a été effectué sur un train continu finisseur. A l'entrée de ce dernier la température de l'acier était de l'ordre de 900°C et à la sortie de l'ordre de 750°C. La bande a alors été bobinée à une température de 750°C. Par la suite, une finition par laminage à froid, à savoir un skinn-pass de 2 %, a été effectuée. Après un décapage chimique classique en milieu sulfurique, un recuit continu a été effectué à une température de 825°C et ce pendant une durée de 90 secondes. Puis enfin la bande a été soumise à une trempe "HOWAQ" à 400°C et à un surveillissement pendant 200 secondes à 400°C suivi d'un nouveau décapage à l'acide formique et d'un nouveau skinn-pass de 0,2 %.The rolling was carried out on a continuous finishing train. At the entry of the latter the temperature of the steel was of the order of 900 ° C. and at the exit of the order of 750 ° C. The strip was then wound at a temperature of 750 ° C. Subsequently, a cold rolling finish, namely a skin pass of 2%, was carried out. After a conventional chemical pickling in a sulfuric medium, continuous annealing was carried out at a temperature of 825 ° C. and this for a period of 90 seconds. Then finally the strip was subjected to a "HOWAQ" quenching at 400 ° C. and to monitoring for 200 seconds at 400 ° C. followed by a further etching with formic acid and a new skin pass of 0, 2%.
La taille de grain dans la bande d'acier terminée était de 2 ASTM et le champ coercitif était égal à 80 A/m.The grain size in the finished steel strip was 2 ASTM and the coercive field was 80 A / m.
L'acier utilisé présentait la composition suivante :
C = 0,003 %
Mn = 0,300 %
S = 0,001 % globulaire
Si = 0,250 %
P = 0,015 %
Al = 0,250 %
V = 0,150 %.The steel used had the following composition:
C = 0.003%
Mn = 0.300%
S = 0.001% globular
If = 0.250%
P = 0.015%
Al = 0.250%
V = 0.150%.
La température de réchauffage était de 1050°C pendant 2 heures.The reheat temperature was 1050 ° C for 2 hours.
La température moyenne au finisseur était de 840°C.The average temperature at the paver was 840 ° C.
La température de bobinage était de 730°C.The winding temperature was 730 ° C.
Un auto-recuit s'est effectué automatiquement en bobine.Self-annealing was performed automatically on the coil.
Ensuite, un déroulage suivi d'un planage de la "tôle noire", c'est-à-dire sans décapage, ont été effectués.Then, an unwinding followed by a leveling of the "black sheet", that is to say without stripping, were carried out.
Cette tôle présentait alors un champ coercitif de 50 A/m et une induction de 1,95 Ts à un champ magnétique de 100 A/cm.This sheet then presented a coercive field of 50 A / m and an induction of 1.95 Ts at a magnetic field of 100 A / cm.
L'acier utilisé présentait la composition suivante :
C = 0,001 %
Nb = 0,015 %
Ti = 0,025 %
N = 0,003 %
S = 0,005 %
P = 0,022 %
Mn = 0,325 %.The steel used had the following composition:
C = 0.001%
Nb = 0.015%
Ti = 0.025%
N = 0.003%
S = 0.005%
P = 0.022%
Mn = 0.325%.
La température de réchauffage était de 1000°C pendant 2 heures 15 minutes.The reheat temperature was 1000 ° C for 2 hours 15 minutes.
La température à l'entrée du finisseur était de 900°C et à la sortie de 675°C.The inlet temperature of the paver was 900 ° C and the outlet temperature of 675 ° C.
La température de bobinage était de 200°C et l'épaisseur de la bande à la sortie du finisseur était de 0,8 mm.The winding temperature was 200 ° C and the thickness of the strip leaving the finisher was 0.8 mm.
Un recuit continu et un décapage à l'hydrogène à 850°C pendant 120 secondes ont été appliqués.Continuous annealing and etching with hydrogen at 850 ° C for 120 seconds were applied.
L'acier obtenu présentait un grain ASTM 1 et un champ coercitif de 40 A/m.The steel obtained had an ASTM 1 grain and a coercive field of 40 A / m.
L'induction était de 0,8 Ts à un champ magnétique de 40 A/m.The induction was 0.8 Ts at a magnetic field of 40 A / m.
L'acier utilisé présentait la composition suivante :
C = 0,017 %
Ti = 0,150 %
Al = 0,025 %
Si = 0,030 %
P = 0,017 %
S = 0,007 %
N = 0,0065 %.The steel used had the following composition:
C = 0.017%
Ti = 0.150%
Al = 0.025%
If = 0.030%
P = 0.017%
S = 0.007%
N = 0.0065%.
La température de réchauffage était de 1250°C pendant 1 heure 30 minutes.The reheating temperature was 1250 ° C for 1 hour 30 minutes.
La température moyenne dans le finisseur était de 760°C.The average temperature in the paver was 760 ° C.
La température de bobinage était de 300°C et ce dernier était suivi d'un décapage chimique.The winding temperature was 300 ° C and this was followed by chemical pickling.
Le recuit a été réalisé dans un milieu d'hydrogène à une température de 750°C.Annealing was carried out in a hydrogen medium at a temperature of 750 ° C.
L'acier obtenu présentait un grain ASTM de 5-6.The steel obtained had an ASTM grain of 5-6.
Le champ coercitif était de 110 A/m.The coercive field was 110 A / m.
L'invention n'est bien entendu pas limitée aux différentes formes de réalisation décrites ci-dessus et, dans le cadre de l'invention, plusieurs variantes peuvent être envisagées, notamment en ce qui concerne le type de recuit et de décapage appliqué. Ainsi, un traitement d'élimination de la calamine peut, si nécessaire, intervenir à différentes étapes du procédé. Ce traitement peut être un décapage chimique ou un décalaminage mécanique tel que, respectivement, une réduction de l'oxyde métallique par un agent réducteur, comme par exemple l'hydrogène, ou un grenaillage.The invention is of course not limited to the various embodiments described above and, within the scope of the invention, several variants can be envisaged, in particular as regards the type of annealing and pickling applied. Thus, a calamine removal treatment can, if necessary, take place at different stages of the process. This treatment can be a chemical pickling or a mechanical descaling such as, respectively, a reduction of the metal oxide by a reducing agent, such as for example hydrogen, or a shot peening.
Par ailleurs, la bande d'acier laminée peut être maintenue à une température sensiblement uniforme relativement basse de tout au plus 150°C avant son enroulement éventuel.Furthermore, the rolled steel strip can be kept at a substantially uniform temperature relatively low at most 150 ° C before its possible winding.
Claims (12)
C ≦ 1 %
Si ≦ 1 %
Mn < 1 %
P < 0,100 %
S < 0,100 %
N < 0,100 %
Al ≦ 0,250 %,
en ce que l'on forme des brames à partir d'un acier présentant la composition susdite, à ce que l'on soumet ces brames à un laminage conduit au moins en partie dans la phase ferritique jusqu'à obtenir une bande d'une épaisseur de 1 à 12 mm et à ce que la bande d'acier ainsi obtenue subit un autorecuit et/ou est soumise à un recuit contrôlé de manière à obtenir une cristallisation de l'acier dans la phase ferritique.Process for the production of mild steel, characterized in that use is made of a steel corresponding to the following composition:
C ≦ 1%
If ≦ 1%
Mn <1%
P <0.100%
S <0.100%
N <0.100%
Al ≦ 0.250%,
in that slabs are formed from a steel having the above composition, in that these slabs are subjected to a rolling process which leads at least partly in the ferritic phase until a strip of a thickness from 1 to 12 mm and that the steel strip thus obtained undergoes a self-annealing and / or is subjected to a controlled annealing so as to obtain a crystallization of the steel in the ferritic phase.
C ≦ 0,010 %
Si ≦ 0,30 %
Mn < 1 %
P < 0,030 %
S < 0,020 %
N < 0,010 %
Al < 0,100 %,
à ce que, après avoir formé des brames à partir d'un acier répondant à cette composition, on soumet ces dernières à un laminage à une température de 200 à 900°C.Process according to Claim 1, characterized in that use is made of a steel corresponding to the following composition:
C ≦ 0.010%
If ≦ 0.30%
Mn <1%
P <0.030%
S <0.020%
N <0.010%
Al <0.100%,
that, after having formed slabs from a steel corresponding to this composition, the latter are subjected to rolling at a temperature of 200 to 900 ° C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE9400140 | 1994-02-07 | ||
| BE9400140A BE1007927A3 (en) | 1994-02-07 | 1994-02-07 | Method for producing mild steel. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0681031A1 true EP0681031A1 (en) | 1995-11-08 |
| EP0681031B1 EP0681031B1 (en) | 2002-01-16 |
Family
ID=3887951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP95200245A Expired - Lifetime EP0681031B1 (en) | 1994-02-07 | 1995-02-02 | Process for manufacturing mild steel |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0681031B1 (en) |
| AT (1) | ATE212070T1 (en) |
| BE (1) | BE1007927A3 (en) |
| DE (1) | DE69524989T2 (en) |
| DK (1) | DK0681031T3 (en) |
| ES (1) | ES2171494T3 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001002611A1 (en) * | 1999-07-05 | 2001-01-11 | Thyssen Krupp Stahl Ag | Method for producing non-grain oriented electric sheet steel |
| WO2003014404A1 (en) * | 2001-08-11 | 2003-02-20 | Thyssenkrupp Electrical Steel Ebg Gmbh | Non-grain oriented electric sheet steel or strip and method for the production thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0263413A2 (en) * | 1986-09-29 | 1988-04-13 | Nippon Kokan Kabushiki Kaisha | Non-oriented electrical steel sheets and producing non-oriented steel sheets |
| GB2226571A (en) * | 1988-12-22 | 1990-07-04 | Sumitomo Metal Ind | Magnetic stool plate for use as a magnetic shielding member and a method for the manufacture thereof |
| FR2643386A1 (en) * | 1989-02-21 | 1990-08-24 | Nippon Kokan Kk | PROCESS FOR PRODUCING NON-ORIENTED MAGNETIC STEEL STRIPES |
| FR2643387A1 (en) * | 1989-02-23 | 1990-08-24 | Nippon Kokan Kk | PROCESS FOR MANUFACTURING NON-ORIENTED MAGNETIC STEEL STRIP |
| EP0388776A1 (en) * | 1989-03-16 | 1990-09-26 | Nippon Steel Corporation | Method of producing non-oriented magnetic steel plate having high magnetic flux density and uniform magnetic properties through the thickness direction |
| JPH02290921A (en) * | 1989-04-28 | 1990-11-30 | Sumitomo Metal Ind Ltd | Production of electro plate for thick plate |
| JPH0353023A (en) * | 1989-07-18 | 1991-03-07 | Sumitomo Metal Ind Ltd | Manufacture of steel sheet for mask flame of cathode-ray tube |
| EP0469980A1 (en) * | 1990-07-30 | 1992-02-05 | Ugine S.A. | Process for manufacturing grain non oriented magnetic steel sheet and sheet obtained thereby |
| EP0609190A1 (en) * | 1993-01-29 | 1994-08-03 | CENTRE DE RECHERCHES METALLURGIQUES CENTRUM VOOR RESEARCH IN DE METALLURGIE Association sans but lucratif | Method of manufacturing a hot rolled steel sheet with high magnetic properties |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69227548T2 (en) * | 1991-07-17 | 1999-07-29 | Centre Rech Metallurgique | Process for producing a thin strip from mild steel |
-
1994
- 1994-02-07 BE BE9400140A patent/BE1007927A3/en not_active IP Right Cessation
-
1995
- 1995-02-02 ES ES95200245T patent/ES2171494T3/en not_active Expired - Lifetime
- 1995-02-02 EP EP95200245A patent/EP0681031B1/en not_active Expired - Lifetime
- 1995-02-02 AT AT95200245T patent/ATE212070T1/en active
- 1995-02-02 DK DK95200245T patent/DK0681031T3/en active
- 1995-02-02 DE DE69524989T patent/DE69524989T2/en not_active Expired - Lifetime
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0263413A2 (en) * | 1986-09-29 | 1988-04-13 | Nippon Kokan Kabushiki Kaisha | Non-oriented electrical steel sheets and producing non-oriented steel sheets |
| GB2226571A (en) * | 1988-12-22 | 1990-07-04 | Sumitomo Metal Ind | Magnetic stool plate for use as a magnetic shielding member and a method for the manufacture thereof |
| FR2643386A1 (en) * | 1989-02-21 | 1990-08-24 | Nippon Kokan Kk | PROCESS FOR PRODUCING NON-ORIENTED MAGNETIC STEEL STRIPES |
| FR2643387A1 (en) * | 1989-02-23 | 1990-08-24 | Nippon Kokan Kk | PROCESS FOR MANUFACTURING NON-ORIENTED MAGNETIC STEEL STRIP |
| EP0388776A1 (en) * | 1989-03-16 | 1990-09-26 | Nippon Steel Corporation | Method of producing non-oriented magnetic steel plate having high magnetic flux density and uniform magnetic properties through the thickness direction |
| JPH02290921A (en) * | 1989-04-28 | 1990-11-30 | Sumitomo Metal Ind Ltd | Production of electro plate for thick plate |
| JPH0353023A (en) * | 1989-07-18 | 1991-03-07 | Sumitomo Metal Ind Ltd | Manufacture of steel sheet for mask flame of cathode-ray tube |
| EP0469980A1 (en) * | 1990-07-30 | 1992-02-05 | Ugine S.A. | Process for manufacturing grain non oriented magnetic steel sheet and sheet obtained thereby |
| EP0609190A1 (en) * | 1993-01-29 | 1994-08-03 | CENTRE DE RECHERCHES METALLURGIQUES CENTRUM VOOR RESEARCH IN DE METALLURGIE Association sans but lucratif | Method of manufacturing a hot rolled steel sheet with high magnetic properties |
Non-Patent Citations (2)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 15, no. 197 (C - 833) 21 May 1991 (1991-05-21) * |
| PATENT ABSTRACTS OF JAPAN vol. 15, no. 64 (C - 806) 15 February 1991 (1991-02-15) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001002611A1 (en) * | 1999-07-05 | 2001-01-11 | Thyssen Krupp Stahl Ag | Method for producing non-grain oriented electric sheet steel |
| WO2003014404A1 (en) * | 2001-08-11 | 2003-02-20 | Thyssenkrupp Electrical Steel Ebg Gmbh | Non-grain oriented electric sheet steel or strip and method for the production thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| BE1007927A3 (en) | 1995-11-21 |
| DE69524989T2 (en) | 2002-08-29 |
| DK0681031T3 (en) | 2002-04-29 |
| EP0681031B1 (en) | 2002-01-16 |
| DE69524989D1 (en) | 2002-02-21 |
| ATE212070T1 (en) | 2002-02-15 |
| ES2171494T3 (en) | 2002-09-16 |
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