WO1997039152A1 - Method for producing a hot-rolled high-tensile steel strip - Google Patents
Method for producing a hot-rolled high-tensile steel strip Download PDFInfo
- Publication number
- WO1997039152A1 WO1997039152A1 PCT/BE1997/000020 BE9700020W WO9739152A1 WO 1997039152 A1 WO1997039152 A1 WO 1997039152A1 BE 9700020 W BE9700020 W BE 9700020W WO 9739152 A1 WO9739152 A1 WO 9739152A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- hot
- steel
- temperature
- cooling
- strip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
Definitions
- the present invention relates to a process for the manufacture of a hot-rolled strip of high-strength steel, intended for direct use, that is to say without hot rolling being followed by cold rolling.
- these steels are now required to have a breaking load (Rm) greater than 550 MPa, a ratio of the elastic limit (Re) to the breaking load (Rm), ie Re / Rm , less than 0.7 and a high ductility, expressed by an elongation (A) greater than 20%.
- the resilience must also be high, for example at least 150 J / cm 2 at -50 ° C, in order to give the steel a high impact resistance. Good oligocyclic fatigue strength and high weldability are also considered essential characteristics.
- the current practice for the manufacture of a hot-rolled strip intended for direct use consists in continuously casting a steel slab whose thickness is generally greater than 150 mm, for example between 150 mm and 300 mm.
- This slab is rolled at high temperature in a roughing rolling mill in order to produce a blank whose thickness is generally between 20 mm and 40 mm.
- This blank is then rolled in a hot finishing train to the desired thickness, most often between 1.5 mm and 5 mm.
- the rolling of the blanks to the final thickness is carried out in full in the austenitic domain, with inlet temperatures to the hot finishing train above 950 ° C.
- the hot strip thus laminated is transferred to a water cooling table and is then wound in the ferritic region with a winding temperature above 500 ° C.
- the high levels of resistance desired for these steels can be obtained by the addition of alloying elements (Mn, Si, Cr, ...), which generate the formation of multi-phase microstructures out of balance under certain cooling and cooling conditions. winding.
- alloying elements Mn, Si, Cr, ...), which generate the formation of multi-phase microstructures out of balance under certain cooling and cooling conditions. winding.
- Obtaining these multiphase steels (ferrite, bainite, martensite, residual austenite, etc.) requires the use of complex cooling cycles comprising accelerated cooling and staged quenching phases. However, these practices may not be compatible with certain applications such as, for example, welding.
- the object of the present invention is to propose a method for manufacturing a hot-rolled strip intended for direct use, which makes it possible to greatly improve the mechanical properties mentioned above while ensuring consistency of these properties along the strip as well. produced.
- a method for manufacturing a hot rolled strip from. high strength steel in which a hot rolled steel is rolled, the carbon, manganese and silicon contents of which are between 0.04% by weight and 0.2%, between 0.5% and 2% and between 0.010% and 0.5% respectively, is characterized in that said steel additionally contains niobium in a content of between 0.01% and 0.1 % by weight, the remainder being iron and usual impurities, in that the hot rolling is carried out to finish said steel between an initial temperature below 950 ° C and a final temperature above the transformation temperature of the austenite made of ferrite (Ar3), with a thickness reduction rate of at least 85%, in that said hot-rolled steel is cooled in a period of less than 5 s with a cooling rate greater than 20 ° C / s from said final temperature to a temperature below 200 ° C and in that said hot rolled steel is coiled at said temperature below 200 ° C.
- the cooling is carried out in as short a time as possible, preferably less than 1 s.
- the cooling speed of the hot rolled steel is between 30 ° C / s and 1000 ° C / s, this value representing an average cooling speed between the temperature finishing and winding temperature.
- this cooling is carried out continuously and monotonously up to said temperature below 200 ° C., called the winding temperature, the highest values of the cooling speed making it possible to increase the elastic limit and the breaking load. without altering the strength-ductility compromise.
- said winding temperature is between 20 ° C and 150 ° C.
- the various aforementioned operations may correspond to successive stages related to the installation itself.
- the initial temperature of the finish rolling normally designates the temperature of entry into the finishing train
- the final temperature designates the temperature of exit from this finishing train
- the cooling of the strip comprises the transfer of the strip between the exit of the train finisher and entry of the cooling section, transfer which must be carried out in as short a time as possible, and the cooling carried out on an appropriate cooling table.
- Table I indicates the chemical composition of the steels used for the manufacture of these strips.
- This table shows the improvements in different mechanical properties observed on the hot strips treated by the two processes.
- These two properties are particularly important for the use of resistance steels.
- the tensile curve of the steel of the invention is continuous and without stepping of the elastic limit, which gives the hot strip of the invention non-aging properties appreciated by users. .
- the improvement in the properties of the hot strips is also visible in the plot of the oligocyclic fatigue resistance curve, shown in the diagram in FIG. 1.
- a strong improvement in the resistance to oligocyclic fatigue is indeed observed in favor of hot rolled steel according to the invention.
- This improvement is expressed by a relative decrease in resistance to 0.25% (R0.25) much less for the steel of the invention (14%) than for the reference steel HSLA (35%), corresponding also at a higher number of cycles (N) for the steel of the invention (45,000) than for the HSLA steel (15,000).
- Fig. 2 shows the evolution of the Charpy resilience (5 mm test pieces) as a function of the test temperature.
- the examination of Table III and of FIG. 2 shows the marked improvement observed in the case of rolled steel according to the method of the invention.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
Procédé pour la fabrication d'une bande laminée à chaud en acier à haute résistance.Process for the manufacture of a hot rolled strip of high strength steel.
La présente invention concerne un procédé pour la fabrication d'une bande laminée à chaud en acier à haute résistance, destinée à être utilisée directement, c'est-à-dire sans que le laminage à chaud soit suivi d'un laminage à froid.The present invention relates to a process for the manufacture of a hot-rolled strip of high-strength steel, intended for direct use, that is to say without hot rolling being followed by cold rolling.
Actuellement, les aciers dits de résistance doivent présenter des propriétés mécaniques de plus en plus élevées afin de répondre à des conditions de mise en oeuvre toujours plus diversifiées et sévères.Currently, so-called resistance steels must have increasingly high mechanical properties in order to respond to increasingly diverse and harsh processing conditions.
En particulier, on exige à présent de ces aciers qu'ils présentent une charge de rupture (Rm) supérieure à 550 MPa, un rapport de la limite d'élasticité (Re) à la charge de rupture (Rm), soit Re/Rm, inférieur à 0.7 et une ductilité élevée, exprimée par un allongement (A) supérieur à 20 %. De plus, la résilience doit également être élevée, par exemple au moins égale à 150 J/cm2 à -50°C, afin de conférer à l'acier une haute résistance aux chocs. Une bonne résistance en fatigue oligocyclique et une soudabilité élevée sont aussi considérées comme des caractéristiques essentielles. Par exemple, la résistance en fatigue oligocyclique sous une déformation de 0,25 % devrait se traduire par une réduction relative de la résistance de moins de 20% après au moins 30.000 cycles, tandis que la soudabilité devrait être assurée par une composition chimique conduisant à un carbone équivalent inférieur à 0,35 %, le carbone équivalent étant défini de façon connue par la relation C,,, = [C + (Mn + Si)/6] où les teneurs des différents éléments sont exprimées en pourcents en poids.In particular, these steels are now required to have a breaking load (Rm) greater than 550 MPa, a ratio of the elastic limit (Re) to the breaking load (Rm), ie Re / Rm , less than 0.7 and a high ductility, expressed by an elongation (A) greater than 20%. In addition, the resilience must also be high, for example at least 150 J / cm 2 at -50 ° C, in order to give the steel a high impact resistance. Good oligocyclic fatigue strength and high weldability are also considered essential characteristics. For example, the oligocyclic fatigue strength under a deformation of 0.25% should result in a relative reduction in strength of less than 20% after at least 30,000 cycles, while the weldability should be ensured by a chemical composition leading to an equivalent carbon lower than 0.35%, the equivalent carbon being defined in a known manner by the relation C ,,, = [C + (Mn + Si) / 6] where the contents of the various elements are expressed in percent by weight.
La pratique actuelle pour la fabrication d'une bande laminée à chaud destinée à être utilisée directement consiste à couler en continu une brame en acier dont l'épaisseur est en général supérieure à 150 mm, par exemple comprise entre 150 mm et 300 mm. Cette brame est laminée à haute température dans un laminoir dégrossisseur afin de produire une ébauche dont l'épaisseur est généralement comprise entre 20 mm et 40 mm. Cette ébauche est ensuite laminée dans un train finisseur à chaud jusqu'à l'épaisseur désirée, le plus souvent comprise entre 1,5 mm et 5mm. Selon la pratique usuelle, le laminage des ébauches jusqu'à l'épaisseur finale est effectué intégralement dans le domaine austénitique, avec des températures d'entrée au train finisseur à chaud supérieures à 950°C. La bande à chaud ainsi laminée est transférée sur une table de refroidissement à l'eau et est ensuite bobinée dans le domaine ferritique avec une température de bobinage supérieure à 500°C.The current practice for the manufacture of a hot-rolled strip intended for direct use consists in continuously casting a steel slab whose thickness is generally greater than 150 mm, for example between 150 mm and 300 mm. This slab is rolled at high temperature in a roughing rolling mill in order to produce a blank whose thickness is generally between 20 mm and 40 mm. This blank is then rolled in a hot finishing train to the desired thickness, most often between 1.5 mm and 5 mm. According to usual practice, the rolling of the blanks to the final thickness is carried out in full in the austenitic domain, with inlet temperatures to the hot finishing train above 950 ° C. The hot strip thus laminated is transferred to a water cooling table and is then wound in the ferritic region with a winding temperature above 500 ° C.
Les hauts niveaux de résistance désirés pour ces aciers peuvent être obtenus par l'addition d'éléments d'alliage (Mn, Si, Cr, ...), qui engendrent la formation de microstructures multiphases hors équilibre dans certaines conditions de refroidissement et de bobinage. L'obtention de ces aciers multiphases (ferrite, bainite, martensite, austénite résiduelle, ...) demande la mise en oeuvre de cycles de refroidissement complexes comprenant des phases de refroidissement accéléré et de trempe étagée. Ces pratiques peuvent cependant ne pas être compatibles avec certaines applications comme par exemple le soudage.The high levels of resistance desired for these steels can be obtained by the addition of alloying elements (Mn, Si, Cr, ...), which generate the formation of multi-phase microstructures out of balance under certain cooling and cooling conditions. winding. Obtaining these multiphase steels (ferrite, bainite, martensite, residual austenite, etc.) requires the use of complex cooling cycles comprising accelerated cooling and staged quenching phases. However, these practices may not be compatible with certain applications such as, for example, welding.
Afin de pallier ces inconvénients, une autre voie de fabrication consiste à utiliser des aciers microalliés (dénommés HSLA) à faible teneur en carbone, pour lesquels le durcissement résulte de la solution solide et de la précipitation. Cette technique a cependant pour effet d'augmenter sensiblement le prix de revient de ce type d'acier. Il est en outre difficile avec ces aciers de respecter la condition Re/Rm <_ 0,7.In order to overcome these drawbacks, another manufacturing route consists in using micro-alloyed steels (called HSLA) with low carbon content, for which hardening results from the solid solution and from precipitation. However, this technique has the effect of significantly increasing the cost price of this type of steel. It is moreover difficult with these steels to comply with the condition Re / Rm <_ 0.7.
Si ces deux solutions connues permettent d'obtenir de hautes performances mécani¬ ques, elles conduisent cependant aussi à une grande dispersion des propriétés mécaniques le long de la bande laminée à chaud, en raison de la difficulté de contrôler le procédé de fabrication avec une précision suffisante.If these two known solutions make it possible to obtain high mechanical performance, they also however lead to a great dispersion of the mechanical properties along the hot-rolled strip, due to the difficulty of controlling the manufacturing process with precision. sufficient.
La présente invention a pour objet de proposer un procédé pour fabriquer une bande laminée à chaud destinée à être utilisée directement, qui permet d'améliorer fortement les propriétés mécaniques mentionnées ci-dessus tout en garantissant une constance de ces propriétés le long de la bande ainsi produite.The object of the present invention is to propose a method for manufacturing a hot-rolled strip intended for direct use, which makes it possible to greatly improve the mechanical properties mentioned above while ensuring consistency of these properties along the strip as well. produced.
Conformément à la présente invention, un procédé pour fabriquer une bande laminée à chaud en. acier à haute résistance, dans lequel on lamine à chaud un acier dont les teneurs en carbone, en manganèse et en silicium sont comprises, en poids, entre 0,04% et 0,2%, entre 0,5% et 2% et entre 0,010 % et 0,5 % respectivement, est caractérisé en ce que ledit acier contient en outre du niobium en une teneur comprise entre 0,01 % et 0, 1 % en poids, le reste étant du fer et des impuretés habituelles, en ce qu'on effectue le laminage à chaud de finition dudit acier entre une température initiale inférieure à 950°C et une température finale supérieure à la température de transformation de l'austénite en ferrite (Ar3), avec un taux de réduction d'épaisseur d'au moins 85 %, en ce que l'on refroidit ledit acier laminé à chaud dans un délai inférieur à 5 s avec une vitesse de refroidissement supérieure à 20°C/s à partir de ladite température finale jusqu'à une température inférieure à 200°C et en ce que l'on bobine ledit acier laminé à chaud à ladite température inférieure à 200°C.According to the present invention, a method for manufacturing a hot rolled strip from. high strength steel, in which a hot rolled steel is rolled, the carbon, manganese and silicon contents of which are between 0.04% by weight and 0.2%, between 0.5% and 2% and between 0.010% and 0.5% respectively, is characterized in that said steel additionally contains niobium in a content of between 0.01% and 0.1 % by weight, the remainder being iron and usual impurities, in that the hot rolling is carried out to finish said steel between an initial temperature below 950 ° C and a final temperature above the transformation temperature of the austenite made of ferrite (Ar3), with a thickness reduction rate of at least 85%, in that said hot-rolled steel is cooled in a period of less than 5 s with a cooling rate greater than 20 ° C / s from said final temperature to a temperature below 200 ° C and in that said hot rolled steel is coiled at said temperature below 200 ° C.
Suivant l'invention, le refroidissement est effectué en un temps aussi court que possible, de préférence inférieur à 1 s.According to the invention, the cooling is carried out in as short a time as possible, preferably less than 1 s.
Suivant une mise en oeuvre particulière du procédé de l'invention, la vitesse de refroidissement de l'acier laminé à chaud est comprise entre 30°C/s et 1000°C/s, cette valeur représentant une vitesse moyenne de refroidissement entre la température de finition et la température de bobinage.According to a particular implementation of the process of the invention, the cooling speed of the hot rolled steel is between 30 ° C / s and 1000 ° C / s, this value representing an average cooling speed between the temperature finishing and winding temperature.
Avantageusement, ce refroidissement est effectué de manière continue et monotone jusqu'à ladite température inférieure à 200°C, dite température de bobinage, les plus hautes valeurs de la vitesse de refroidissement permettant d'augmenter la limite d'élasticité et la charge de rupture sans altérer le compromis résistance-ductilité..Advantageously, this cooling is carried out continuously and monotonously up to said temperature below 200 ° C., called the winding temperature, the highest values of the cooling speed making it possible to increase the elastic limit and the breaking load. without altering the strength-ductility compromise.
Suivant une caractéristique avantageuse, ladite température de bobinage est comprise entre 20°C et 150°C.According to an advantageous characteristic, said winding temperature is between 20 ° C and 150 ° C.
Pour la mise en oeuvre pratique du procédé sur un train de laminage de finition, les différentes opérations précitées peuvent correspondre à des étapes successives rapportées à l'installation elle-même. Ainsi, la température initiale du laminage de finition désigne normalement la température d'entrée dans le train finisseur, la température finale désigne la température de sortie de ce train finisseur, le refroi¬ dissement de la bande comprend le transfert de la bande entre la sortie du train finisseur et l'entrée de la section de refroidissement, transfert qui doit être effectué en un temps aussi court que possible, et le refroidissement effectué sur une table de refroidissement appropriée.For the practical implementation of the process on a finishing rolling train, the various aforementioned operations may correspond to successive stages related to the installation itself. Thus, the initial temperature of the finish rolling normally designates the temperature of entry into the finishing train, the final temperature designates the temperature of exit from this finishing train, the cooling of the strip comprises the transfer of the strip between the exit of the train finisher and entry of the cooling section, transfer which must be carried out in as short a time as possible, and the cooling carried out on an appropriate cooling table.
Le procédé de l'invention et les avantages qui en découlent sont à présent illustrés par deux exemples de bandes à chaud destinées à être utilisées directement, à savoir une bande en acier HSLA fabriquée de manière conventionnelle (1 ) et une bande fabriquée selon le procédé de la présente invention (2).The method of the invention and the advantages which result therefrom are now illustrated by two examples of hot strips intended for direct use, namely a HSLA steel strip produced in a conventional manner (1) and a strip produced according to the process. of the present invention (2).
Le tableau I indique la composition chimique des aciers utilisés pour la fabrication de ces bandes.Table I indicates the chemical composition of the steels used for the manufacture of these strips.
Tableau I : Composition chimique des aciers (% poids)Table I: Chemical composition of steels (% by weight)
Les deux bandes ont été fabriquées dans les conditions indiquées dans le TableauThe two bands were manufactured under the conditions indicated in the Table
Tableau II : Paramètres de fabrication des bandesTable II: Manufacturing parameters of the bands
Les propriétés mécaniques des bandes à chaud, fabriquées d'une part par le procédé conventionnel (1 ) et d'autre part par le procédé de l'invention (2), sont exprimées par les résultats d'essais repris dans le Tableau III.
Ce tableau montre les améliorations de différentes propriétés mécaniques observées sur les bandes à chaud traitées par les deux procédés. On constate une augmentation importante de la charge de rupture Rm de l'ordre de 180 MPa en faveur de la bande à chaud fabriquée par le procédé de l'invention. Ceci s'accompagne d'une diminution du rapport Re/Rm de 0.87 pour l'acier HSLA conventionnel à 0.53 pour l'acier obtenu suivant l'invention. Ces deux propriétés sont particulièrement importantes pour la mise en oeuvre des aciers de résistance. Il faut en outre noter que la courbe de traction de l'acier de l'invention est continue et sans palier de la limite d'élasticité, ce qui confère à la bande à chaud de l'invention des propriétés non vieillissantes appréciées par les utilisateurs.This table shows the improvements in different mechanical properties observed on the hot strips treated by the two processes. There is a significant increase in the breaking load Rm of the order of 180 MPa in favor of the hot strip manufactured by the method of the invention. This is accompanied by a reduction in the Re / Rm ratio from 0.87 for the conventional HSLA steel to 0.53 for the steel obtained according to the invention. These two properties are particularly important for the use of resistance steels. It should also be noted that the tensile curve of the steel of the invention is continuous and without stepping of the elastic limit, which gives the hot strip of the invention non-aging properties appreciated by users. .
L'amélioration des propriétés des bandes à chaud est également visible dans le tracé de la courbe de résistance en fatigue oligocyclique, représentée dans le diagramme de la Fig. 1. Une forte amélioration de la résistance en fatigue oligocyclique est en effet observée en faveur de l'acier laminé à chaud suivant l'invention. Cette amélioration s'exprime par une décroissance relative de la résistance à 0,25% (R0,25) beaucoup moindre pour l'acier de l'invention (14 %) que pour l'acier de référence HSLA (35 %), correspondant également à un nombre de cycles (N) plus élevé pour l'acier de l'invention (45000) que pour l'acier HSLA (15000).The improvement in the properties of the hot strips is also visible in the plot of the oligocyclic fatigue resistance curve, shown in the diagram in FIG. 1. A strong improvement in the resistance to oligocyclic fatigue is indeed observed in favor of hot rolled steel according to the invention. This improvement is expressed by a relative decrease in resistance to 0.25% (R0.25) much less for the steel of the invention (14%) than for the reference steel HSLA (35%), corresponding also at a higher number of cycles (N) for the steel of the invention (45,000) than for the HSLA steel (15,000).
La Fig. 2 montre l'évolution de la résilience Charpy (éprouvettes de 5 mm) en fonction de la température d'essai. En ce qui concerne les propriétés de résistance, l'examen du Tableau III et de la Fig. 2 montre la nette amélioration observée dans le cas de l'acier laminé suivant le procédé de l'invention. Fig. 2 shows the evolution of the Charpy resilience (5 mm test pieces) as a function of the test temperature. With regard to the strength properties, the examination of Table III and of FIG. 2 shows the marked improvement observed in the case of rolled steel according to the method of the invention.
Claims
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE69707660T DE69707660T2 (en) | 1996-04-16 | 1997-02-24 | METHOD FOR PRODUCING A STEEL STRIP OF HIGH STRENGTH BY ROLLING ROLLERS |
| EP97903163A EP0894149B1 (en) | 1996-04-16 | 1997-02-24 | Method for producing a hot-rolled high-tensile steel strip |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE9600324A BE1010142A6 (en) | 1996-04-16 | 1996-04-16 | Method for producing a hot rolled strip steel high strength. |
| BE9600324 | 1996-04-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1997039152A1 true WO1997039152A1 (en) | 1997-10-23 |
Family
ID=3889675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/BE1997/000020 Ceased WO1997039152A1 (en) | 1996-04-16 | 1997-02-24 | Method for producing a hot-rolled high-tensile steel strip |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0894149B1 (en) |
| BE (1) | BE1010142A6 (en) |
| DE (1) | DE69707660T2 (en) |
| WO (1) | WO1997039152A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000055381A1 (en) * | 1999-03-13 | 2000-09-21 | Thyssen Krupp Stahl Ag | Method of producing a hot-rolled strip |
| WO2003031669A1 (en) * | 2001-10-04 | 2003-04-17 | Nippon Steel Corporation | High-strength thin steel sheet drawable and excellent in shape fixation property and method of producing the same |
| EP1362930A4 (en) * | 2001-02-23 | 2004-11-24 | Nippon Steel Corp | THIN SHEET OF STEEL WITH EXCELLENT FAITGUE RESISTANCE FOR A MOTOR VEHICLE, AND PRODUCTION METHOD |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008010062A1 (en) * | 2007-06-22 | 2008-12-24 | Sms Demag Ag | Process for hot rolling and heat treatment of a strip of steel |
| CN116875786B (en) * | 2023-04-27 | 2025-08-15 | 唐山不锈钢有限责任公司 | Production method of BJ770 steel belt and method for preparing straight-seam cantilever crane steel pipe by using same |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3102831A (en) * | 1960-08-10 | 1963-09-03 | Molybdenum Corp | Production of columbium containing steels |
| US3849209A (en) * | 1972-02-01 | 1974-11-19 | Nippon Steel Corp | Manufacturing method of high tension, high toughness steel |
| US4184898A (en) * | 1977-07-20 | 1980-01-22 | Nippon Kokan Kabushiki Kaisha | Method of manufacturing high strength low alloys steel plates with superior low temperature toughness |
| US4188241A (en) * | 1977-12-06 | 1980-02-12 | Nippon Steel Corporation | Method for producing high tensile strength, high ductility, low yield ratio hot rolled steel sheet |
| FR2446323A1 (en) * | 1979-01-12 | 1980-08-08 | Nippon Steel Corp | PROCESS FOR THE MANUFACTURE OF TWO-PHASE STEEL SHEETS HAVING HIGH TENSILE STRENGTH AND A LOW-ELASTIC LIMIT / TENSILE STRENGTH AS WELL AS EXCELLENT AGING PROPERTIES AFTER WORK, AND THE PRODUCT THUS OBTAINED |
-
1996
- 1996-04-16 BE BE9600324A patent/BE1010142A6/en not_active IP Right Cessation
-
1997
- 1997-02-24 EP EP97903163A patent/EP0894149B1/en not_active Revoked
- 1997-02-24 WO PCT/BE1997/000020 patent/WO1997039152A1/en not_active Ceased
- 1997-02-24 DE DE69707660T patent/DE69707660T2/en not_active Revoked
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3102831A (en) * | 1960-08-10 | 1963-09-03 | Molybdenum Corp | Production of columbium containing steels |
| US3849209A (en) * | 1972-02-01 | 1974-11-19 | Nippon Steel Corp | Manufacturing method of high tension, high toughness steel |
| US4184898A (en) * | 1977-07-20 | 1980-01-22 | Nippon Kokan Kabushiki Kaisha | Method of manufacturing high strength low alloys steel plates with superior low temperature toughness |
| US4188241A (en) * | 1977-12-06 | 1980-02-12 | Nippon Steel Corporation | Method for producing high tensile strength, high ductility, low yield ratio hot rolled steel sheet |
| FR2446323A1 (en) * | 1979-01-12 | 1980-08-08 | Nippon Steel Corp | PROCESS FOR THE MANUFACTURE OF TWO-PHASE STEEL SHEETS HAVING HIGH TENSILE STRENGTH AND A LOW-ELASTIC LIMIT / TENSILE STRENGTH AS WELL AS EXCELLENT AGING PROPERTIES AFTER WORK, AND THE PRODUCT THUS OBTAINED |
Non-Patent Citations (1)
| Title |
|---|
| YOKOI T ET AL: "DEVELOPMENT OF HOT-ROLLED GALVANNEALED HIGH-STRENGTH STEEL SHEETS WITH GOOD STRETCH FLANGEABILITY", CAHIERS D'INFORMATIONS TECHNIQUES DE LA REVUE DE METALLURGIE, PARIS, FR, vol. 89, no. 2, 1 February 1992 (1992-02-01), pages 163 - 170, XP000267962 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000055381A1 (en) * | 1999-03-13 | 2000-09-21 | Thyssen Krupp Stahl Ag | Method of producing a hot-rolled strip |
| US6855218B1 (en) | 1999-03-13 | 2005-02-15 | Thyssen Krupp Stahl Ag | Method for producing a hot-rolled strip |
| EP1362930A4 (en) * | 2001-02-23 | 2004-11-24 | Nippon Steel Corp | THIN SHEET OF STEEL WITH EXCELLENT FAITGUE RESISTANCE FOR A MOTOR VEHICLE, AND PRODUCTION METHOD |
| WO2003031669A1 (en) * | 2001-10-04 | 2003-04-17 | Nippon Steel Corporation | High-strength thin steel sheet drawable and excellent in shape fixation property and method of producing the same |
| US7503984B2 (en) | 2001-10-04 | 2009-03-17 | Nippon Steel Corporation | High-strength thin steel sheet drawable and excellent in shape fixation property and method of producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| BE1010142A6 (en) | 1998-01-06 |
| EP0894149B1 (en) | 2001-10-24 |
| DE69707660T2 (en) | 2002-06-20 |
| DE69707660D1 (en) | 2001-11-29 |
| EP0894149A1 (en) | 1999-02-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1913169B1 (en) | Manufacture of steel sheets having high resistance and excellent ductility, products thereof | |
| EP1819461B1 (en) | Method of producing austentic iron/carbon/manganese steel sheets having very high strength and elongation characteristics and excellent homogeneity | |
| EP2855725B1 (en) | Low-density hot- or cold-rolled steel, method for implementing same and use thereof | |
| JP5864619B2 (en) | Hot rolled flat steel product manufactured from composite phase steel and method for manufacturing the same | |
| EP3704280B1 (en) | Martensitic stainless steel and method for producing same | |
| WO2012127136A2 (en) | Hot-rolled steel sheet and associated production method | |
| EP2155915A2 (en) | Process for manufacturing cold-rolled and annealed steel sheets with very high strength, and sheets thus produced | |
| WO2012153008A1 (en) | Method for the production of very-high-strength martensitic steel and sheet or part thus obtained | |
| EP1427866A1 (en) | Method for making rolled and welded tubes comprising a final drawing or hydroforming step and resulting rolled tube | |
| EP1587963B1 (en) | Ultrahigh strength hot-rolled steel and method of producing bands | |
| BE1010142A6 (en) | Method for producing a hot rolled strip steel high strength. | |
| EP0747496B1 (en) | Hot rolled steel sheet with high strength and good deep-drawing properties, containing titanium and process for its manufacturing | |
| FR2833617A1 (en) | PROCESS FOR MANUFACTURING COLD ROLLED SHEATHES WITH HIGH RESISTANCE OF MICRO-ALLOY DUAL PHASE STEELS | |
| EP1138796B1 (en) | High strength hot rolled steel with high yield strength for use in the car industry | |
| EP1099769A1 (en) | Process for manufacturing high tensile strength hot rolled steel sheet for forming and especially for deep drawing | |
| EP2257652B1 (en) | Method of manufacturing sheets of austenitic stainless steel with high mechanical properties | |
| FR2477178A1 (en) | Low yield point, high strength steel plate for automobiles - contains silicon, manganese, with chromium and/or molybdenum, has mixed ferrite-martensite structure | |
| BE1010093A6 (en) | Method of manufacturing a hot-rolled strip of high-tensile steel | |
| EP4347903A1 (en) | Hot-formed steel part and manufacturing method | |
| FR2748033A1 (en) | Low alloy steel sheet which is readily shaped |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): JP US |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
| DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| WWE | Wipo information: entry into national phase |
Ref document number: 1997903163 Country of ref document: EP |
|
| WWP | Wipo information: published in national office |
Ref document number: 1997903163 Country of ref document: EP |
|
| NENP | Non-entry into the national phase |
Ref country code: JP Ref document number: 97536593 Format of ref document f/p: F |
|
| WWG | Wipo information: grant in national office |
Ref document number: 1997903163 Country of ref document: EP |
|
| WWW | Wipo information: withdrawn in national office |
Ref document number: 1997903163 Country of ref document: EP |