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
  • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
• • 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
  • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
  • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
  • C21D8/0473—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
  • C21D9/48—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
• • 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
• • 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
  • C21D2201/00—Treatment for obtaining particular effects
  • C21D2201/05—Grain orientation
• • 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 steel plate for cans suitable for can container materials used for food and beverage cans and a method for producing the same.
• the present invention relates to a steel plate for cans that is suitable as a steel plate for a three-piece can and has excellent buckling strength of the can body against external pressure, and a method for manufacturing the same.
• the buckling deformation of the can body part is caused by the deterioration of the rigidity of the can body due to the thinning of the thickness of the can body part. Therefore, in order to improve the buckling deformation resistance (sometimes referred to as paneling strength), a method of improving the rigidity by increasing the Young's modulus of the steel sheet itself can be considered. In other words, in a three-piece can in which the direction perpendicular to the rolling direction is the circumferential direction of the can body, the buckling deformation resistance of the can body can be improved by improving the Young's modulus in the direction perpendicular to the rolling direction.
• the Young's modulus of iron and the crystal orientation of the steel sheet, and the ⁇ 110> direction developed by rolling is parallel to the rolling direction. Can be increased. Further, the crystal orientation group ( ⁇ fiber) in which the ⁇ 111> direction is parallel to the normal direction of the plate surface can increase the Young's modulus in the 0 °, 45 °, and 90 ° directions to about 220 GPa with respect to the rolling direction. On the other hand, when the crystal orientation of the steel sheet does not show orientation in a specific orientation, that is, the Young's modulus of the steel sheet with a random texture is about 205 GPa.
• Patent Document 1 after cold-annealing steel containing the above chemical components, secondary cold rolling of 50% or more is performed to form a strong rolling texture, and the Young's modulus in the 90 ° direction with respect to the rolling direction is set. It has been disclosed to increase the rigidity of the steel sheet by increasing it.
• Patent Document 2 in mass%, C: 0.003% or less, Si: 0.02% or less, Mn: 0.05 to 0.60%, P: 0.02% or less, S: 0 0.02% or less, Al: 0.01 to 0.10%, N: 0.0010 to 0.0050%, Nb: 0.001 to 0.05%, B: 0.0005 to 0.002%
• the balance is made of Fe and inevitable impurities, and ( ⁇ 112 ⁇ ⁇ 110> orientation accumulation strength) / ( ⁇ 111 ⁇ ⁇ 112> orientation accumulation strength) ⁇ 1.0 in the central portion of the plate thickness,
• a high-strength steel sheet for cans is disclosed which has a tensile strength in the 90 ° direction from the rolling direction of 550 to 800 MPa and a Young's modulus in the 90 ° direction from the rolling direction of 230 GPa or more.
• Patent Document 1 has a problem that neck formability and flange formability are deteriorated by secondary rolling at a high reduction ratio of 50% or more.
• Patent Document 2 the strength in the 90 ° direction from the rolling direction is increased by recovery annealing, and thus there is a problem that a stable roll form property (rolled shape) cannot be obtained.
• Patent Document 3 although excellent buckling strength can be obtained, sufficient hardness of the steel plate that can resist deformation of the can body due to external force acting during the can manufacturing process, transport process and handling in the market. There is a problem that it cannot always be obtained.
• the present invention has been made in view of such circumstances, solves the above-mentioned problems of the prior art, has a sufficient hardness, and has excellent buckling strength of the can body against external pressure, and a method for manufacturing the same.
• the purpose is to provide.
• the gist of the present invention is as follows.
• C 0.005% or more and 0.020% or less, Si: 0.05% or less, Mn: 0.50% or more and 1.00% or less, P: 0.030 by mass% %: S: 0.020% or less, Al: 0.01% to 0.04%, N: 0.0010% to 0.0050%, B: 0.0005% to 0.0040%
• [2] Furthermore, as a component composition, Ti: 0.005% or more and 0.030% or less in terms of mass%, the crystal grain size measured at a ferrite grain size of 7.0 ⁇ m or less and a thickness of 1/4 part
• the steel plate for cans as described in [1].
• [3] A steel slab having the composition described in [1] or [2] is hot-rolled at a finishing temperature of 800 to 900 ° C.
• a method for producing a steel plate for cans that is cold-rolled at a rolling reduction of at least%, annealed at an annealing temperature of 700 ° C. to 750 ° C., and then temper-rolled.
• the strength required in the can making process and the transport process and the buckling strength of the can body against the external pressure are the reference values (about 1.5 kgf / cm 2 ) higher can body, that is, a can body having sufficient strength and sufficient rigidity can be easily manufactured. Therefore, according to the present invention, the rigidity of the can used for food cans, beverage cans, and the like is improved, and the steel sheet can be further thinned to achieve resource saving and cost reduction. It has a remarkable industrial effect. Moreover, the application range of the steel sheet according to the present invention can be expected to be applied not only to various metal cans but also to a wide range of dry battery interior cans, various home appliances / electrical parts, automotive parts and the like.
• C 0.005% or more and 0.020% or less
• C has the effect of increasing the hardness by refining the ferrite grain size and the effect of increasing the hardness by existing as solid solution C. Furthermore, by making C 0.005% or more and 0.020% or less, it is possible to promote the development of ⁇ fiber and improve the Young's modulus in the direction perpendicular to the rolling. On the other hand, when C is less than 0.005%, a texture mainly composed of ⁇ fibers develops, and a high Young's modulus in the direction perpendicular to the rolling direction cannot always be obtained. For this reason, C content needs to be 0.005% or more.
• the C content is 0.015% or less.
• Si 0.05% or less
• Si content needs to be 0.05% or less.
• the Si content is 0.02% or less.
• Mn 0.50% or more and 1.00% or less Mn is an important element in the present invention.
• MnS there is an effect of preventing a decrease in hot ductility due to S contained in the steel.
• the Mn content needs to be 0.50% or more.
• the Mn content is 0.60% or more.
• the Mn content exceeds 1.00%, the texture hardly develops during annealing, and the Young's modulus in the direction perpendicular to the rolling decreases. For this reason, the upper limit of the Mn content is 1.00%.
• P 0.030% or less
• the upper limit of the P content is 0.030%.
• the P content is 0.020% or less.
• S 0.020% or less S forms sulfides in steel and reduces hot ductility. Therefore, the S content is 0.020% or less. Preferably, the S content is 0.015% or less.
• Al 0.01% or more and 0.04% or less
• Al is an element contained as a deoxidizer.
• N and AlN it has the effect of reducing the solid solution N in steel and improving the formability and aging resistance.
• N 0.0010% or more and 0.0050% or less N combines with Al, B and the like to form nitrides and carbonitrides and increases hardness. On the other hand, since it reduces hot ductility, it is so preferable that it is small. Further, when N is contained in a large amount, the development of the texture is inhibited and the Young's modulus is lowered. For this reason, the upper limit of the N content is set to 0.0050%. Preferably, the N content is 0.0035% or less. As described above, N is preferably as low as possible. However, when the N content is less than 0.0010%, not only the effect on the texture is saturated but also the effect of increasing the hardness due to the nitride cannot be obtained. For this reason, the lower limit of the N content is set to 0.0010%.
• B 0.0005% or more and 0.0040% or less B lowers the Ar 3 transformation point to refine the crystal grains of the hot-rolled sheet and promotes the development of the texture and suppresses the grain growth in the annealing process. effective. Moreover, there exists an effect which improves hardness by refine
• the lower limit of the B content needs to be 0.0005%.
• the lower limit of the B content is 0.0010%.
• the upper limit of B content needs to be 0.0040%.
• the B content is 0.0030% or less.
• Ti 0.005% or more and 0.030% or less Ti has the effect of suppressing the generation of BN by making a nitride preferentially with N, and ensuring B that works effectively for fine graining. Further, by making the crystal grain of the hot-rolled sheet finer by the pinning effect of TiN or TiC, it has the effect of promoting the development of the texture and improving the Young's modulus in the direction perpendicular to the rolling. For this reason, it is preferable to contain Ti 0.005% or more. From the viewpoint of fixing N, the Ti content is more preferably 0.008% or more. On the other hand, when Ti is excessively contained, nitrides and carbides are coarsely formed, the pinning effect is lost, and the fine graining effect cannot be obtained. Furthermore, the moldability is significantly reduced. For this reason, it is preferable to make the upper limit of Ti content 0.030%. More preferably, the Ti content is 0.025% or less.
• the balance is iron and inevitable impurities.
• the HR30T hardness can be set to 58 or more.
• a desired ferrite particle size can be obtained by controlling the coiling temperature, the cold rolling rate, and the annealing temperature described later.
• the grain size of ferrite means the grain size of recrystallized ferrite measured according to the steel-crystal grain size microscopic test method of JIS G 0551. Even when the non-recrystallized ferrite structure contains 1% or less in area ratio and cementite contains 0.3% or less in area ratio, the effects of the present invention can be obtained.
• the steel sheet of the present invention does not contain martensite, bainite, and retained austenite.
• ⁇ By controlling the texture composed mainly of fibers, the Young's modulus in the direction perpendicular to the rolling can be improved.
• this average integrated strength is 5.0 or more.
• the average integrated strength in the orientation is preferably 15.0 or less. As will be described later, a desired average integrated strength can be obtained by controlling the coiling temperature and the cold rolling reduction and recrystallizing in the annealing step.
• Rockwell superficial hardness (HR30T) 58 or more
• the Rockwell superficial hardness (HR30T) is 60 or more.
• it is preferably 70 or less from the viewpoint of ensuring workability. More preferably, it is 66 or less.
• the direction perpendicular to rolling In a three-piece can of 220 GPa or more, the direction perpendicular to rolling is the circumferential direction of the can body. For this reason, excellent buckling resistance can be obtained by improving the Young's modulus in the direction perpendicular to the rolling.
• the Young's modulus in the direction perpendicular to the rolling needs to be 220 GPa or more.
• the Young's modulus in the direction perpendicular to the rolling is 225 GPa or more.
• the Young's modulus in the direction perpendicular to the rolling is preferably 245 Ga or less. .
• the steel plate for cans according to the present invention is hot rolled on a steel slab having the above composition at a finishing temperature of 800 to 900 ° C. during hot rolling, and then wound at a winding temperature of 500 to 650 ° C. and reduced by 85% or more. It is preferably manufactured by cold rolling at a rate, annealing at an annealing temperature of 700 to 750 ° C., and then performing temper rolling.
• the finish rolling temperature during hot rolling 800 ⁇ 900 °C
• the finish rolling temperature at the time of hot rolling is higher than 900 ° C.
• the grain size of the hot rolled sheet becomes coarse, which inhibits the development of the texture, and the ferrite grain diameter of the annealed sheet becomes coarse and the hardness decreases. . Therefore, the finish rolling temperature during hot rolling is set to 900 ° C. or lower.
• the finish rolling temperature at the time of hot rolling is less than 800 ° C., the rolling becomes below the transformation point, and the texture does not develop due to the formation of coarse grains and the remaining rolling structure. Therefore, the finish rolling temperature during hot rolling is set to 800 ° C. or higher.
• the finish rolling temperature during hot rolling is 830 ° C or higher.
• the slab heating temperature prior to hot rolling need not be specified. However, when Ti is contained, the slab heating temperature is preferably 1100 ° C. or higher from the viewpoint of redissolving coarse TiC and TiN present in the slab.
• the coiling temperature exceeds 650 ° C.
• the grain size of the hot rolled sheet becomes coarse, and the carbides also become coarse so that the ferrite grain size of the annealed sheet becomes coarse, and the hardness of the annealed sheet decreases.
• the coiling temperature is set to 650 ° C. or less.
• the coiling temperature is 630 ° C. or lower.
• winding temperature shall be 500 degreeC or more.
• the surface scale can be removed by pickling or physical removal. Pickling and physical removal may be carried out individually or in combination.
• the pickling conditions are not particularly limited as long as the surface scale can be removed. Pickling can be performed by a conventional method.
• Cold rolling reduction ratio 85% or more
• the cold rolling reduction ratio is 85% or more so that the Young's modulus improvement and hardness in the direction perpendicular to the rolling due to the development of the texture are set to predetermined values.
• the rolling reduction rate is preferably 88% or more. More preferably, the rolling reduction of cold rolling is 90% or more.
• Annealing temperature 700-750 ° C
• the annealing temperature is set to 700 ° C. or higher for recrystallization. If the temperature is too high, the ferrite grain size becomes coarse and the hardness decreases. For this reason, annealing temperature shall be 750 degrees C or less.
• annealing temperature shall be 750 degrees C or less.
• the annealing method is not particularly limited. However, the continuous annealing method is preferable from the viewpoint of material uniformity.
• Temper rolling In the present invention, the steel sheet after annealing is subjected to temper rolling from the viewpoints of shape correction and adjustment of surface roughness and hardness. From the viewpoint of suppressing the occurrence of stretcher strain, it is preferable to perform rolling at a rolling reduction of 0.5% or more. On the other hand, when rolling at a rolling reduction exceeding 5.0%, the steel sheet becomes hard and the workability decreases. For this reason, the rolling reduction during temper rolling is preferably 5.0% or less.
• the thickness of the plate is not particularly limited, but is preferably 0.18 mm or less, more preferably 0.16 mm or less from the viewpoint of thinning.
• the steel sheet for cans having sufficient hardness according to the present invention and excellent in the buckling strength of the can body against external pressure can be obtained.
• Steels having the composition of steel symbols A to K shown in Table 1 were melted to obtain steel slabs.
• the obtained steel slab was heated and hot-rolled under the conditions shown in Table 2, and after removing the scale by pickling, it was cold-rolled and annealed in a continuous annealing furnace for a soaking time of 15 seconds. went.
• temper rolling was performed to obtain steel plates (steel symbols 1 to 20) having a thickness of 0.16 mm.
• Ferrite grain size is determined by etching the ferrite structure of the cross section in the rolling direction with a 3% nital solution to reveal grain boundaries, and using a 400 ⁇ photograph taken with an optical microscope, steel of JIS G 0551 -Measured by the cutting method in accordance with the microscopic test method for grain size.
• a crystal orientation distribution function (ODF: Orientation Distribution Function) is calculated from these pole figures by a series expansion method, and the values of ODF in (0, 0, 45) to (0, 55, 45) of Euler space (Bunge system).
• ODF Orientation Distribution Function
• a 10 ⁇ 35 mm test piece having a 90 ° direction as a longitudinal direction with respect to the Young's modulus rolling direction perpendicular to the rolling direction is cut out, and using a lateral vibration type resonance frequency measuring device, in accordance with American Society for Testing Materials standard (C1259).
• the Young's modulus (GPa) in the direction perpendicular to the rolling was measured.
• Buckling strength of can body after can making Three-piece can molding was performed on the obtained steel plate.
• the blank was rolled so that the direction perpendicular to rolling was the circumferential direction of the can body, and the ends were joined by welding to obtain a can having a diameter of 52 mm and a can body height of 96 mm.
• the method for measuring the buckling strength of the can body is as follows.
• the can body was placed inside the pressure chamber and pressurized.
• the pressurization inside the pressurization chamber was stopped at the time when 0.016 MPa per second was introduced into the chamber through the air introduction valve and the can was buckled.
• the pressure inside the chamber was confirmed through a pressure gauge, a pressure sensor, an amplifier that amplifies the detection signal, a signal processing device that performs display of the detection signal, data processing, and the like.
• the buckling pressure was the pressure at the pressure change point accompanying buckling.
• the external pressure strength is required to exceed 0.15 MPa with respect to the pressure change caused by the heat sterilization treatment. From this, the case where the external pressure strength was higher than 0.15 MPa was rated as ⁇ , and the case where the external pressure strength was 0.15 MPa or less was rated as x.
• the examples of the present invention all have an HR30T hardness of 58 or more, a Young's modulus in the direction perpendicular to the rolling of 220 GPa or more, and have excellent buckling strength as a can body.
• the Young's modulus in the direction perpendicular to the rolling was less than 220 GPa, and the buckling strength was inferior.

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)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54194685

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (2)

• 2015
  • 2015-03-23 JP JP2015537036A patent/JP5900711B2/ja active Active
  • 2015-03-23 WO PCT/JP2015/001633 patent/WO2015146136A1/ja active Application Filing
  • 2015-03-27 TW TW104110073A patent/TWI537398B/zh active

Patent Citations (2)

Also Published As

Similar Documents

Legal Events