WO2008020580A1 - Feuilles d'acier à haute teneur en carbone laminées à chaud et leur procédé de production - Google Patents

Feuilles d'acier à haute teneur en carbone laminées à chaud et leur procédé de production Download PDF

Info

Publication number
WO2008020580A1
WO2008020580A1 PCT/JP2007/065788 JP2007065788W WO2008020580A1 WO 2008020580 A1 WO2008020580 A1 WO 2008020580A1 JP 2007065788 W JP2007065788 W JP 2007065788W WO 2008020580 A1 WO2008020580 A1 WO 2008020580A1
Authority
WO
WIPO (PCT)
Prior art keywords
less
temperature
steel sheet
cooling
hot
Prior art date
Application number
PCT/JP2007/065788
Other languages
English (en)
Japanese (ja)
Inventor
Shunji Iizuka
Kenichi Mitsuzuka
Naoya Aoki
Hideyuki Kimura
Nobuyuki Nakamura
Kazuhiro Seto
Akio Kobayashi
Original Assignee
Jfe Steel Corporation
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jfe Steel Corporation filed Critical Jfe Steel Corporation
Priority to US12/373,903 priority Critical patent/US20090260729A1/en
Priority to KR1020087030308A priority patent/KR101084874B1/ko
Priority to CN2007800269001A priority patent/CN101490296B/zh
Publication of WO2008020580A1 publication Critical patent/WO2008020580A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C21D1/32—Soft annealing, e.g. spheroidising
    • 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
    • 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
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Definitions

  • the present invention relates to a high carbon hot-rolled copper sheet and a method for producing the same, and more particularly to a high carbon hot-rolled steel sheet having excellent uniformity in the width direction and a method for producing the same. ⁇ 3 ⁇ 4jutsu
  • High-carbon steel sheets used for tools or automobile parts (gears, missions), etc. are subjected to heat treatment such as quenching and tempering after stamping.
  • tool and component manufacturers that is, users of high carbon steel sheets, have been able to reduce the cost by cutting parts of former forging materials and parts processing by hot forging by pressing copper plates (including cold forging). Simplification of the process is being considered for machining.
  • high carbon copper sheets as raw materials are strongly demanded for hardenability and processing stability into complex shapes.
  • stability of material properties is strongly required from the viewpoint of press machine and die maintenance.
  • Patent Document 1 proposes a method of manufacturing a high carbon steel strip that is heated to a two-phase region of ferrite toustenite at a predetermined heating rate after hot rolling and is annealed at a predetermined cooling rate. Yes.
  • a high carbon steel strip is annealed in a two-phase region of ferrite and austenite above the Acl point, resulting in a structure in which coarse spheroidizing cementite is uniformly distributed in the ferrite matrix.
  • heating rate Tv (° C / Hr): 500X (0.01-0.01% in a temperature range of 680 ° C or higher in an atmosphere furnace consisting of 95% by volume of hydrogen and the balance nitrogen N (%) asAIN) 2000X (0.1—N (%) asAlN), Soaking temperature TA (.C) Acl point ⁇ 222XC (%) 2 — 411 XC (%) + 912 Soaking time 1 Annealing in 20 hours Cooling to room temperature at a cooling rate of 100 ° C / Hr or less.
  • Patent Document 2 C 0.1 0.8 mass%, S: 0., 01 mass y.
  • the hot-rolled copper sheet containing the following hold the first stage of heating for 0.5 hours or more in the temperature range of Acl_50 ° C Acl.
  • the third stage heating holding for 2 to 20 hours in the temperature range of ⁇ Arl A manufacturing method has been proposed in which the cooling rate from the second stage holding temperature to the third stage holding temperature is 5-30 / 11. That is, Patent Document 2 seeks to obtain a high-carbon steel sheet having an average grain size of 20 / zm or more by performing three-step annealing in this way.
  • Patent Document 3 is hot rolled on steel containing 0.2 to 0.7 mass%, and after controlling to a structure having a volume ratio exceeding 70%, annealing is performed.
  • a method has been proposed in which the ferritite grains are uniformly coarsened to make them extremely soft. This technique involves hot rolling at a finishing temperature of at least 20 (Ar3 transformation point) and then cooling. At a cooling rate exceeding 120 ° C / second and at the following cooling end temperature at 550, then winding at a coiling temperature of 500 ° C or less, pickling, and annealing temperature below the Acl transformation point It is characterized by annealing.
  • Patent Document 1 Japanese Patent Laid-Open No. 9-157758
  • Patent Document 2 Japanese Patent Laid-Open No. 11-80884
  • Patent Document 3 Japanese Patent Laid-Open No. 2003-73742 Disclosure of Invention ''
  • Patent Document 1 a high-carbon steel strip is annealed in a two-phase region of ferrite toustenite with an Acl point or higher, and a coarse spheroidizing cementite is formed. It is a difficult structure to stabilize the workability and workability.
  • the present invention has been made in view of such circumstances, and does not require a complicated manufacturing process, has a stable hardenability and press formability, and has a high carbon hot-rolled steel sheet with excellent uniformity in the width direction, and its production.
  • the purpose is to provide a manufacturing method. In particular, it aims to stabilize the structure near the edge of the steel plate. '
  • the inventors of the present invention have made extensive studies on the effects of the component composition, the structure of the mixture and the production conditions on the homogeneity in the width direction of the high carbon steel sheet. As a result, it was found that it is important to define the average particle size of the fly and the average particle size of carbides over the entire width of the steel sheet in order to obtain excellent uniformity in the width direction.
  • the hardenability and press formability are stabilized by controlling the ferrite average grain size at the edge of the steel plate and the ferrite average particle size and carbide average particle size at the center of the steel plate edge portion within the appropriate ranges. It was confirmed that a high-carbon hot-rolled steel sheet with excellent uniformity in the width direction could be obtained.
  • the present invention has been made based on the above findings, and the gist thereof is as follows.
  • finish rolling is performed at a finishing temperature exceeding (Ar3 + 40 ° C), and then after finishing rolling Cool within 2 seconds at a cooling rate of over 120 ° C / second to a cooling end temperature of over 550 ° C and below 650 ° C, then scraped at a temperature below 550, pickled, and then box-annealed 670 ⁇ :
  • the percentages indicating the copper component are all mass%.
  • a high-carbon hot-rolled steel sheet that can stably ensure hardenability and press formability and has excellent uniformity in the width direction can be obtained.
  • the high carbon excellent in the homogeneity in the width direction of the present invention Hot-rolled steel sheet can be manufactured without using special annealing conditions. As a result, it is possible to achieve a high yield at the time of manufacturing and to reduce the cost.
  • the high-carbon hot-rolled steel sheet of the present invention is controlled to have the following composition, and the ferrite average particle size at the steel plate edge portion is less than 35 ⁇ , and the ferrite average particle size at the center portion than the steel plate edge portion is Less than 20 / zm, and carbide average particle size is 0. ⁇ ! ! ! more than? ⁇ ! ! ! It is characterized by having an organization that is less than. These are the most important requirements in the present invention. In this way, by defining the component composition and metal structure (ferrite average particle size by width direction classification) and carbide shape (carbide average particle size) and satisfying all of them, it is safe in the width direction including the edge part.
  • the steel plate edge portion is between 25 and 75 thighs from both sides in the steel plate width direction during hot rolling.
  • the range of 75 mm from both sides in the width direction of the steel sheet it is easy to overcool and temperature control is difficult. Therefore, the variation in organization increases.
  • the range of 25 mm from both sides in the width direction of the copper plate is generally a part that is not subject to quality assurance or is cut off by side trimming.
  • a range of 25 to 75 mm from both sides in the width direction of the steel sheet is referred to as a “steel edge portion”, and the structure in this range is improved to approach the structure near the center in the width direction of the steel sheet.
  • the high carbon hot-rolled steel sheet having excellent uniformity in the width direction is obtained by roughly rolling a steel having the composition described later, and then performing finish rolling at a finishing temperature exceeding (Ar3 + 40t). Next, within 2 seconds after finish rolling, cooling is performed at a cooling rate exceeding 120 ° C / second to a cooling end temperature exceeding 550 ° C and less than 650 ° C, and then picked at a temperature of 550 ° C or less and pickled. Thereafter, it is manufactured by spheroidizing annealing at a temperature of not less than 670 and not more than the Acl transformation point by a box annealing method.
  • the object of the present invention is achieved by controlling the production conditions from hot finish rolling, cooling after finish rolling, scraping and annealing.
  • C is the most basic alloying element in carbon steel.
  • the quenching hardness and the amount of carbide in the annealed state vary greatly depending on the content. For steels with a C content of less than 0.2%, Sufficient quenching hardness is not obtained for application to automotive parts.
  • the C content exceeds 0.7%, the toughness after hot rolling decreases, and the manufacturability and handling of the steel strip deteriorates, so that stable production is impossible and it is difficult to reduce the cost. Therefore, from the viewpoint of providing a steel sheet having appropriate quenching hardness and press formability at a low cost, the C content is not less than 0.2% and not more than 0.7%, preferably not less than 0.2% and 0.5. % Or less.
  • Si is an element that improves hardenability. If the Si content is less than 0.01%, the hardness during quenching is insufficient. On the other hand, when the Si content exceeds 1.0%, the ferrite hardens due to solid solution strengthening, and the press formability deteriorates. Further, the carbide tends to be graphitized and the hardenability is hindered. Therefore, from the viewpoint of providing a steel sheet having both appropriate quenching hardness and press formability, the Si content is from 0.01% to 1%, preferably from 0.01% to 0.8%. And
  • Mn is an element that improves hardenability like Si. It is also an important element that fixes S as MnS and prevents hot cracking of the slab. If the Mn content is less than 0.1%, these effects cannot be obtained sufficiently, and the hardenability is greatly reduced. On the other hand, when the Mn content exceeds 1.0%, the ferrite is hardened due to solid solution strengthening, and press formability is deteriorated. Therefore, from the viewpoint of providing a steel sheet having both appropriate quenching hardness and press formability, the Mn content is 0.1% or more and 1.0% or less, preferably 0.1% or more and 0.8% or less. And
  • the P content is 0.03% or less, preferably 0.0023 ⁇ 4 or less.
  • the S content is acceptable up to 0.035%, the S content is 0.035% or less, preferably 0.030% or less.
  • the A1 content should be 0.08% or less, preferably 0.06% or less.
  • N 0.01% or less
  • N is contained in excess, it will cause a decrease in ductility, so the N content is o.oiy. Below The
  • the steel of the present invention can achieve the desired characteristics, but in addition to the above essential additive elements, Mo, in order to suppress the formation of proeutectoid ferrite during hot rolling cooling and to improve hardenability, Ti or Nb may be added alone or in combination as required. In that case, if the addition amount of Mo is less than 0.005%, Ti is less than 0.005%, and Nb is less than 0.005%, the effect of addition may not be sufficiently obtained. On the other hand, when Mo exceeds 0.5%, Ti exceeds 0.05%, and Nb exceeds 0.1%, the effect is saturated and the cost increases, and the strength increases greatly due to solid solution strengthening and precipitation strengthening. Therefore, workability may deteriorate.
  • Mo is 0.005% or more and 0.5% or less
  • Ti is 0.005% or more and 0.05% or less
  • Nb is 0.005% or more and 0.1% or less.
  • the balance other than the above consists of Fe and inevitable impurities.
  • Cu, Ni, W, V, Zr, Sn, and Sb may be contained in a range of 0.1% or less as trace elements that do not impair the effects of the present invention.
  • Ferrite average particle size at the edge of the copper plate less than 35 / ⁇ ⁇
  • the ferrite average particle size should be less than 35 im.
  • the steel plate central portion rather than the copper plate edge portion. The difference is preferably 15 m or less.
  • a steel sheet having an average ferrite grain size of less than 35 / m at the edge of the copper sheet can be obtained by controlling the temperature and cooling conditions during finish rolling, as will be described later. Specifically, a steel sheet having an average particle size of less than 35 / zm at the edge portion of the steel sheet is roughly rolled, then finish-rolled at a finishing temperature exceeding (Ar3 + 40t), and then It is obtained by cooling to a cooling end temperature of over 550 ° C and less than 650 ° C at a cooling rate of over 120 ° C / second within 2 seconds after finish rolling.
  • the average ferrite grain size is an important factor governing the stability of press forming. In other words, excellent additive properties can be obtained by adjusting the ferritic average particle size to less than 20 / cm2) and having few coarse particles. Therefore, the average ferrite particle size at the center of the copper plate should be less than 20 / zm. On the other hand, if it is too fine, the hardness becomes high and the mold life may be reduced.
  • a copper plate having a ferrite average particle size of less than 20 / xm at the center of the steel plate can be obtained by controlling the temperature and cooling conditions during finish rolling, as will be described later. Specifically, after rough rolling, finish rolling with a finishing temperature exceeding (Ar3 + 40 ° C) is performed, and then at a cooling rate exceeding 120 ° C / second within 2 seconds after finishing rolling. It can be obtained by cooling to a cooling end temperature of less than 650: over ° C.
  • the carbide average particle size is an important requirement because it greatly affects the press formability, punching workability, and quenching strength in the heat treatment stage after press forming.
  • the carbide becomes finer, the carbide is easily dissolved in the heat treatment stage after processing, and a stable quenching hardness can be ensured.
  • the average particle size of the carbide is less than 0. ⁇ , the press formability increases as the hardness increases. to degrade.
  • the press formability improves as the average carbide particle size increases, but if it exceeds 2.0 / im, the carbide becomes difficult to dissolve in the heat treatment stage after processing, and the quenching hardness decreases.
  • the average particle size of carbide should be 0.10 / im or more and less than 2.0 mm.
  • the carbide average particle size can be controlled by the production conditions, particularly the cooling conditions after hot rolling, the coiling temperature, and the annealing conditions as described later.
  • the high carbon hot-rolled copper sheet having excellent uniformity in the width direction of the present invention is obtained by roughly rolling a steel adjusted to the above chemical component range, finish rolling at a desired finishing temperature, and then cooling under desired cooling conditions. It is obtained by performing desired spheroidizing annealing by a box-type annealing method after scouring and pickling. These are described in detail below.
  • the finishing temperature (rolling temperature in the final pass) when hot rolling the steel is below (Ar3 + 40) ° C, -Stennai
  • the part where many shear bands are introduced in the grains is formed at the edge of the steel sheet, and the nucleation site for transformation increases. For this reason, the ferrite grains become finer, and coarse ferrite grains are often generated especially at the edge of the steel sheet, using high grain boundary energy as the driving force during spheroidizing annealing. Therefore, the finishing temperature should exceed (Ar3 + 40) ° C.
  • the finishing temperature is preferably above (Ar3 + 80) ° C.
  • the upper limit of the finishing temperature is not particularly specified, but at a high temperature exceeding lOOOt, scale defects are likely to occur.
  • the finishing temperature (rolling temperature in the final pass) when hot-rolling steel exceeds (Ar3 + 40) ° C.
  • the Ar3 transformation point (° C) can be calculated by the following equation (1).
  • Ar3 910-310C-80Mn- 15Cr-80Mo (1)
  • the element symbol in a formula represents content (mass%) of each element.
  • the cooling rate after hot rolling is over 120 ° C / sec. Preferably it is 200 / sec or more.
  • the upper limit of the cooling rate is not particularly limited, for example, assuming a plate thickness of 3.0 mm, it is 700 ° C / second from the current facility capacity.
  • the time from finish rolling to the start of cooling should be within 2 seconds.
  • the time from finish rolling to the start of cooling is preferably within 1.5 seconds, and more preferably within 1.0 seconds.
  • Cooling end temperature Over 550 ° C and under 650 ° C
  • the cooling stop temperature after hot rolling is 550 ° C or less
  • a fine bainite structure may be generated at the hot-rolled sheet stage, especially at the edge of the steel plate where the temperature is low, which is coarse after the final annealing.
  • a ferritic grain structure is formed, and a uniform structure cannot be obtained in the width direction.
  • a coarse ferrite toprite structure is formed at the hot-rolled sheet stage, and the carbides after annealing. Is dispersed unevenly and a stable sized structure cannot be obtained. Therefore, the cooling stop temperature should be over 550 and under 650.
  • the trapping temperature is 550T: or less.
  • the lower limit of the coiling temperature is not specified, but the shape of the steel sheet deteriorates as the temperature becomes lower, so it is preferable to set the temperature to 200 ° C or higher.
  • the hot-rolled copper sheet after cutting is pickled to remove scale before spheroidizing annealing.
  • Pickling may be performed according to a conventional method.
  • Spheroidizing annealing can be broadly divided into: (l) A method in which it is heated to a temperature just above Acl and then slowly cooled, (2) A method in which it is kept at a temperature just below Acl for a long time, and (3) There is a way to repeat.
  • the method (2) above the grain growth of the ferrite grains and the spheroidization of the carbide are simultaneously directed.
  • the annealing temperature for spheroidizing annealing is 670 ° C or more and Acl transformation point or less, preferably 670 ° C or more and 710 ° C.
  • the Acl transformation point (° C) can be calculated by the following equation (2).
  • the element symbol in a formula represents content (mass%) of each element.
  • the high carbon hot rolled sheet steel excellent in the homogeneity in the width direction of the present invention is obtained.
  • a converter or an electric furnace can be used to adjust the components of the high carbon steel of the present invention.
  • the high-carbon steel whose components are adjusted in this way is used as a steel slab, which is a copper material, by ingot lump rolling or continuous forging.
  • This steel slab is hot-rolled.
  • the slab heating temperature is preferably 1300 ° C. or less in order to avoid deterioration of the surface state due to scale generation.
  • Direct feed rolling may be performed.
  • finish rolling may be performed by omitting rough rolling during hot rolling.
  • the rolled material may be heated by a heating means such as a bar heater or an edge heater during hot rolling. Further, in order to promote spheroidization or reduce hardness, the coil may be kept warm by means such as a slow cooling cover after cutting. After annealing, temper rolling is performed as necessary. Since this temper rolling does not affect the hardenability, there are no particular restrictions on the conditions.
  • the reason why the high carbon hot-rolled steel sheet thus obtained has excellent press formability while maintaining hardenability is considered as follows.
  • the homogeneity of the material which is an index of press formability, is greatly influenced by the average particle size of the niobate, the structure is sized, and the press formability is limited by restricting the inclusion of coarse ferrite particle size. Will improve.
  • the average particle size of carbides greatly affects the hardenability. When the carbide is coarse, undissolved carbide tends to remain during solution treatment before quenching, and the quenching hardness decreases.
  • the component composition, metal structure (ferrite average particle size), and carbide shape (carbide average particle size) are specified, and satisfying all of them while ensuring hardenability and press formability.
  • a high carbon hot-rolled steel sheet with excellent directional uniformity can be obtained.
  • Copper having the chemical components shown in Table 1 is continuously produced, and the obtained slab is heated to 1250 ° C, hot-rolled under the conditions shown in Table 2, pickled, and then subjected to the conditions shown in Table 2. Then, spheroidizing annealing was performed by a box-type annealing method to produce a hot-rolled steel sheet with a thickness of 4.0 mm.
  • the average particle size was an average value of 500 or more carbides.
  • Table 3 shows the results obtained from the above measurements.
  • the manufacturing conditions of copper plates Nos. 1 to 10 and 19 to 25 are within the scope of the present invention, and the average ferrite grain size at the edge of the steel plate is less than 35 m, and the average ferrite particle size at the center of the steel plate is 20 m.
  • coarse grains do not occur at the edge of the steel plate, the material hardness difference (A HRB) between the center of the copper plate and the steel plate edge is 10 points or less, and the hardness in the width direction is also stable.
  • copper plates Nos. 11 to 18 and 26 to 29 are comparative examples in which the production conditions are out of the scope of the present invention.
  • Steel plate 14 ⁇ . 14, 18, 26-29 has many coarse grains at the edge of the copper plate, and the average particle size is over 35 ⁇ , which is outside the scope of the present invention. .
  • the difference in material hardness between the central part of the steel sheet and the edge part of the steel sheet exceeds 10 points, a homogeneous material cannot be obtained in the width direction, and the press formability is not stable.
  • Steel plates Nos. 11 to 13 and 15 to 17 have a large average ferrite grain size in the central portion of the steel plate and insufficient strength of the structure.
  • the fulite average particle size and carbide average particle size are outside the scope of the present invention. As a result, hardenability and press formability were not stable.
  • the high carbon hot-rolled steel sheet with excellent homogeneity in the width direction of the present invention it is possible to easily process complex shaped parts such as transmission parts represented by gears with a low load. It can be used for a variety of purposes, centering on tools or automobile parts (gears, missions).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Metal Rolling (AREA)

Abstract

La présente invention concerne une feuille d'acier à haute teneur en carbone laminée à chaud présentant une excellente homogénéité dans la direction de la largeur. Ladite feuille d'acier contient C : 0,2 à 0,7 %, Si : 0,01 à 1,0 %, Mn : 0,1 à 1,0 %, P : 0,03 % ou moins, S : 0,035 % ou moins, Al : 0,08 % ou moins et N : 0,01 % ou moins, le reste étant constitué de Fe et des impuretés inévitables. La texture de la feuille est caractérisée par une grosseur de grain de ferrite moyenne au bord de la feuille de moins de 35 μm, une grosseur de grain de ferrite moyenne dans la zone centrale de moins de 20 μm et une grosseur de grain de carbure moyenne comprise entre 0,10 μm et moins de 2,0 μm. Ladite feuille d'acier est fabriquée par laminage brut, laminage de finition à une température de finition de (Ar3+40 °C) ou plus, refroidissement initié dans les deux secondes suivant le laminage de finition à une vitesse de refroidissement supérieure à 120 °C/s jusqu'à une température d'arrêt de refroidissement supérieure à 550 °C et inférieure à 650 °C, enroulement à une température de 550 °C ou moins, décapage puis globulisation à une température de 670 °C jusqu'au point de transformation Ac1.
PCT/JP2007/065788 2006-08-16 2007-08-06 Feuilles d'acier à haute teneur en carbone laminées à chaud et leur procédé de production WO2008020580A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US12/373,903 US20090260729A1 (en) 2006-08-16 2007-08-06 High-carbon hot-rolled steel sheet and method for producing the same
KR1020087030308A KR101084874B1 (ko) 2006-08-16 2007-08-06 고탄소 열연강판 및 그 제조방법
CN2007800269001A CN101490296B (zh) 2006-08-16 2007-08-06 高碳热轧钢板及其制造方法

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2006-221885 2006-08-16
JP2006221885 2006-08-16
JP2007-200672 2007-08-01
JP2007200672A JP5262012B2 (ja) 2006-08-16 2007-08-01 高炭素熱延鋼板およびその製造方法

Publications (1)

Publication Number Publication Date
WO2008020580A1 true WO2008020580A1 (fr) 2008-02-21

Family

ID=39082105

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2007/065788 WO2008020580A1 (fr) 2006-08-16 2007-08-06 Feuilles d'acier à haute teneur en carbone laminées à chaud et leur procédé de production

Country Status (5)

Country Link
US (1) US20090260729A1 (fr)
JP (1) JP5262012B2 (fr)
KR (1) KR101084874B1 (fr)
CN (1) CN101490296B (fr)
WO (1) WO2008020580A1 (fr)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101128942B1 (ko) * 2008-12-24 2012-03-27 주식회사 포스코 열처리 특성이 우수한 미세구상화 강판 및 그 제조방법
JP5440203B2 (ja) * 2010-01-22 2014-03-12 Ｊｆｅスチール株式会社 高炭素熱延鋼板の製造方法
JP5549450B2 (ja) * 2010-07-21 2014-07-16 Ｊｆｅスチール株式会社 ファインブランキング性に優れた高炭素熱延鋼板およびその製造方法
CN101956129A (zh) * 2010-09-23 2011-01-26 舞阳钢铁有限责任公司 一种大厚度结构件用钢板及其生产方法
US8810646B2 (en) 2010-10-12 2014-08-19 Kla-Tencor Corporation Focus offset contamination inspection
IN2014KN01254A (fr) * 2012-01-05 2015-10-16 Jfe Steel Corp
CN104160053B (zh) * 2012-03-08 2016-11-23 日立金属株式会社 碳工具钢钢带
RU2556442C1 (ru) * 2014-10-21 2015-07-10 Юлия Алексеевна Щепочкина Сталь
TWI605133B (zh) * 2015-05-26 2017-11-11 Nippon Steel & Sumitomo Metal Corp Steel plate and its manufacturing method
US20180171445A1 (en) * 2015-06-17 2018-06-21 Nippon Steel & Sumitomo Metal Corporation Steel plate and method of production of same
KR101720234B1 (ko) 2015-12-14 2017-03-28 (주)아이피어브로드 국제 특허 출원 시스템 및 방법
JP6728929B2 (ja) * 2016-04-20 2020-07-22 日本製鉄株式会社 加工性及び焼入れ・焼戻し後の耐摩耗特性に優れる高炭素鋼板及びその製造方法
CN107916373A (zh) * 2016-10-09 2018-04-17 抚顺市鑫盛挖掘机配件制造有限公司 一种35SiMnTi钢种
CN106498293B (zh) * 2016-11-08 2019-01-22 攀钢集团攀枝花钢铁研究院有限公司 一种热成形用高碳热连轧酸洗钢带的制备方法
KR101889173B1 (ko) * 2016-12-13 2018-08-16 주식회사 포스코 고강도 저항복비형 미세 구상화 강판 및 그 제조방법
CN107099649A (zh) * 2017-04-24 2017-08-29 湖北东舟重工科技股份有限公司 一种中碳锰钢两相区亚温正火细化组织的热处理方法
CN111655893B (zh) * 2018-01-30 2022-05-03 杰富意钢铁株式会社 高碳热轧钢板及其制造方法
CN112301275B (zh) * 2020-09-30 2022-05-17 首钢集团有限公司 一种500MPa级高强钢及其制备方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003013144A (ja) * 2001-06-28 2003-01-15 Nkk Corp 伸びフランジ性に優れた高炭素冷延鋼板の製造方法
JP2003073742A (ja) * 2001-08-31 2003-03-12 Nkk Corp 高焼入れ性高炭素熱延鋼板の製造方法
JP2005133200A (ja) * 2003-10-10 2005-05-26 Jfe Steel Kk 高炭素冷延鋼板およびその製造方法
JP2005290547A (ja) * 2004-03-10 2005-10-20 Jfe Steel Kk 延性および伸びフランジ性に優れた高炭素熱延鋼板およびその製造方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3848444B2 (ja) * 1997-09-08 2006-11-22 日新製鋼株式会社 局部延性および焼入れ性に優れた中・高炭素鋼板
US20050199322A1 (en) * 2004-03-10 2005-09-15 Jfe Steel Corporation High carbon hot-rolled steel sheet and method for manufacturing the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003013144A (ja) * 2001-06-28 2003-01-15 Nkk Corp 伸びフランジ性に優れた高炭素冷延鋼板の製造方法
JP2003073742A (ja) * 2001-08-31 2003-03-12 Nkk Corp 高焼入れ性高炭素熱延鋼板の製造方法
JP2005133200A (ja) * 2003-10-10 2005-05-26 Jfe Steel Kk 高炭素冷延鋼板およびその製造方法
JP2005290547A (ja) * 2004-03-10 2005-10-20 Jfe Steel Kk 延性および伸びフランジ性に優れた高炭素熱延鋼板およびその製造方法

Also Published As

Publication number Publication date
US20090260729A1 (en) 2009-10-22
JP5262012B2 (ja) 2013-08-14
KR101084874B1 (ko) 2011-11-21
JP2008069452A (ja) 2008-03-27
CN101490296B (zh) 2011-09-28
KR20090007798A (ko) 2009-01-20
CN101490296A (zh) 2009-07-22

Similar Documents

Publication Publication Date Title
JP5050433B2 (ja) 極軟質高炭素熱延鋼板の製造方法
JP5262012B2 (ja) 高炭素熱延鋼板およびその製造方法
JP5292698B2 (ja) 極軟質高炭素熱延鋼板およびその製造方法
CN107614726B (zh) 钢板及其制造方法
JP4650006B2 (ja) 延性および伸びフランジ性に優れた高炭素熱延鋼板およびその製造方法
CN111406124B (zh) 高强度冷轧钢板及其制造方法
JP5358914B2 (ja) 極軟質高炭素熱延鋼板
JP4600196B2 (ja) 加工性に優れた高炭素冷延鋼板およびその製造方法
JP2009035816A (ja) 降伏強度が低く、材質変動の小さい高強度冷延鋼板の製造方法
JPWO2019151017A1 (ja) 高強度冷延鋼板、高強度めっき鋼板及びそれらの製造方法
JP5302840B2 (ja) 伸びと伸びフランジ性のバランスに優れた高強度冷延鋼板
JP3879446B2 (ja) 伸びフランジ性に優れた高炭素熱延鋼板の製造方法
JP3879459B2 (ja) 高焼入れ性高炭素熱延鋼板の製造方法
JP4696853B2 (ja) 加工性に優れた高炭素冷延鋼板の製造方法および高炭素冷延鋼板
JP3879447B2 (ja) 伸びフランジ性に優れた高炭素冷延鋼板の製造方法
JP4696753B2 (ja) 打抜き加工性に優れた高炭素冷延鋼板の製造方法および高炭素冷延鋼板
JP4622609B2 (ja) 伸びフランジ性に優れた軟質高加工性高炭素熱延鋼板の製造方法
JP4412094B2 (ja) 高炭素冷延鋼板およびその製造方法
JP2003073740A (ja) 高焼入れ性高炭素冷延鋼板の製造方法
WO2020175665A1 (fr) Tôle en acier, élément, et procédé de fabrication de ceux-ci
JP2013124399A (ja) 強度および延性のばらつきの小さい高強度冷延鋼板およびその製造方法

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200780026900.1

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07792431

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 1020087030308

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 12373903

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

122 Ep: pct application non-entry in european phase

Ref document number: 07792431

Country of ref document: EP

Kind code of ref document: A1