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
  • C21D1/34—Methods of heating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/02—Stamping using rigid devices or tools
  • B21D22/022—Stamping using rigid devices or tools by heating the blank or stamping associated with heat treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/20—Deep-drawing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/20—Deep-drawing
  • B21D22/22—Deep-drawing with devices for holding the edge of the blanks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D37/00—Tools as parts of machines covered by this subclass
  • B21D37/16—Heating or cooling
• • 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
  • C21D1/62—Quenching devices
  • C21D1/673—Quenching devices for die quenching
• • 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
  • C21D2221/00—Treating localised areas of an article
• • 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
  • C21D2221/00—Treating localised areas of an article
  • C21D2221/02—Edge parts

Definitions

• the invention relates to a forming tool for press hardening and tempered forming a board made of higher and / or ultra high strength steels with means for temperature control of the forming tool and a method for press hardening and tempered forming of blanks of higher and / or higher strength steels, wherein the board before the forming is heated and then hot formed in a forming tool, wherein the forming tool comprises means for temperature control.
• a board is first heated. This usually happens in an oven. Subsequently, the heated board is removed from the oven and placed in a forming tool in which the board are hot formed. For example, during press-hardening, the board is heated to at least austenitizing temperature. Subsequently, the board cools rapidly, transforming the austenitic structure of the board into a martensitic structure.
• German Offenlegungsschrift DE 198 34 510 A1 discloses a fine blanking tool in which a heating plate with heating elements is arranged in each of the cutting plate and in the guide plate and a temperature sensor for controlling the heating plates is provided.
• a temperature sensor for controlling the heating plates.
• a problem with the forming tools known from the prior art is that although they allow a temperature of the forming tool, a precise control of the board temperature during forming can not be done.
• the object of the present invention is to propose a forming tool for press-hardening and tempered forming as well as a method for press-hardening and tempered forming, which enables a precisely defined temperature control of the blank during the forming process.
• the above-described object is achieved for a generic forming tool in that in the forming a plurality of controllable means for controlling the temperature of the forming tool are provided by which a plurality of temperature zones can be tempered in the forming tool, wherein at least the contact surfaces the forming tool elements used for forming are assigned to individual temperature zones.
• Cooling rates of the board is set during the forming in the individual temperature zones on the temperature difference to the board temperature.
• different material properties can be adjusted in the board. For example, stress relieving may be performed during and / or after forming over the controlled temperature zones.
• the regulation of the individual temperature zones can be improved in that at least one of the number of temperature zones corresponding number of means are provided for measuring temperature.
• these can be assigned to the individual means for temperature control of the temperature zones, so that temperature measured values of each individual temperature zone can be measured.
• thermocouples are commonly used.
• These are preferably arranged so that the temperature of the contact surfaces of individual forming tool elements involved in the forming can be measured. For example, this can be achieved by arranging the temperature sensors in the immediate vicinity of the contact surfaces. On the other hand, it is possible to carry out the position of the means for measuring the temperature of the contact surface via highly thermally conductive inserts and still obtain information about the temperature of the contact surface.
• heating cartridges, heating spirals, heating wires or media guides for tempered active media are provided as means for controlling the temperature.
• Suitable tempered active media are for example oil, water or gas, wherein the tempered active media can ensure both a heat release and a heat absorption.
• the heating cartridges, heating coils or heating wires do not allow any warm discharge on their part, but are particularly easy to integrate into the forming tool and easily controlled.
• the said means for temperature control in a particularly simple manner controlled by the fact that driving means are provided which the Use the temperature of the means for controlling the temperature of the forming tool and the measured temperatures of the individual temperature zones to regulate the heat release and / or -aufnähme the means for controlling the temperature of the forming tool.
• driving means are provided which the Use the temperature of the means for controlling the temperature of the forming tool and the measured temperatures of the individual temperature zones to regulate the heat release and / or -aufnähme the means for controlling the temperature of the forming tool.
• Forming tool receiving the forming tool and / or for thermal insulation of individual Umformwerkmaschinemaschine provided with each other The thermal insulation of Umformwerkmaschinemaschine technique causes on the one hand, that no unnecessary heat dissipation via the Umformwerkmaschinemaschinesch.
• the thermal insulation of individual forming tool elements leads to one another that a temperature profile of the individual forming tool elements and thus a temperature profile of the individual temperature zones can be set in a more reliable manner.
• a fine martensitic structure can be adjusted by setting an average cooling rate.
• At least one drawing ring, at least one stamp and at least one blank holder are provided as forming tool elements, wherein the contact surfaces of the drawing ring, the punch and / or the blank holder form individually controllable temperature zones with the blank, a simple forming tool for press hardening and tempered forming of a blank can be made higher - and / or ultrahigh-strength steel are made available.
• the forming tool is at least for heating of portions of the forming tool to below the AC 3 temperature, in particular to a maximum of 650 0 C, designed.
• the board is at Press-hardening at temperatures in the range of the AC 3 temperature inserted in the forming tool and cools down in the mold so that the forming tool, at least briefly, the AC 3 - Temperature can assume.
• a tempering of the board in the forming tool can be done.
• the above-described object is achieved by a generic method in that the circuit board is formed via contact surfaces of forming tools provided in the forming tool for forming, wherein the contact surfaces are at least partially associated with a plurality of temperature zones provided in the forming tool and a plurality At temperature zones of the forming tool via means for temperature control during the forming in each case be tempered to predefined temperature values.
• a precise control of the temperatures of the board during forming during press hardening and tempered forming of blanks of higher and / or very high strength steels is of particular importance, because then not only the hot forming properties can be controlled well, but also on the Cooling rates influence on the microstructure can be taken. According to the invention this is achieved by the individually controllable temperature zones, which are assigned to the contact surfaces of Umformtechnikmaschinen. Preferably, the temperature zones in the forming tool during the forming uniform or different temperatures. Depending on requirements, during the forming process a temperature profile can be set within the board or a constant temperature in the formed areas of the board.
• cost-effective forming tools can of a next further embodiment of the method may be used in accordance characterized in that the temperature of the individual temperature zones during the forming process does not exceed a maximum temperature of 650 0 C in the forming tool.
• inexpensive hot work tools can be used to make the forming tool.
• the Gefuge can be adjusted pressgeharteten the board in this temperature zone to an improved elongation at break under reduced values with respect to the yield and tensile strength.
• Gefugeschwankeptept due to a higher mold temperature Gefugeschwankept reduced due to changing surface pressures. The reason for this is considered to be that the fluctuation in the cooling rates is reduced despite higher surface pressures at higher mold temperatures.
• the temperature of at least one temperature zone in the forming tool does not exceed 200 ° C., maximum yield strengths and tensile strengths are achieved in this area with a reduced breaking elongation.
• Another parameter for influencing the structure of the board during forming can be provided by the fact that the cooling behavior of the board is at least partially adjusted via the surface pressures of the forming tool. Especially in areas of low temperatures in the forming tool, ie in areas with a temperature below 200 0 C, a variation of the surface pressure leads to significantly different cooling rates, so that the structure of the board is variable in particular in these temperature zones on the surface pressure.
• Particularly high mechanical strength values can be achieved with the method according to the invention by using, for example, a manganese-boron steel, in particular an alloy type 22MnB5 manganese-boron steel.
• Tensile strengths of greater than 1500 MPa and yield strengths of more than 1000 MPa can be achieved with the steel type mentioned, the elongation at break A80 being approximately 5%.
• the boards according to the invention have a surface coating for protection against oxide formation.
• a corresponding oxide protection of the surfaces of the board can be provided by an aluminum-silicon coating.
• a microstructure with the method according to the invention can be adjusted in a targeted manner, that a temperature difference between the heated board and the contact surfaces of the tempered tool between 50 and 650 0 C, preferably from 100 to 350 ° C is set.
• the temperature of the board is understood here as the core temperature of the board.
• At a temperature difference of 50 0 C to 650 0 C almost all microstructures can be generated during forming, such as a ferritic matrix with low temperature differences at 50 0 C.
• At larger temperature differences between 100 0 C and 300 0 C are essentially bainitic microstructures by generates the forming in the board, which have a positive effect on the elongation behavior of the formed board.
• At larger temperature differences of more than 300 0 C is essentially the martensitic
• the single FIGURE shows a perspective sectional view of an embodiment of a forming tool according to the invention for press hardening and tempered forming of a board of higher and / or higher strength steels.
• the illustrated in the single figure embodiment of a forming tool according to the invention for press hardening and tempered forming has first as Umformwerkmaschinemaschinemaschine a drawing ring 1, a stamp 2 and a blank holder 3.
• heating wires 5 are arranged, which temper the drawing ring 1 as the first temperature zone.
• the stamp 2 has a heating coil 6, so that its temperature can also be regulated.
• the receptacle 7 of the sheet metal holder comprises heating wires 8, which temper the sheet metal holder 3.
• the individual temperature zones, which are formed from the contact surfaces of the drawing ring 1, the punch 2 and the sheet holder 3 with the board and the individual heating wires are insulated by insulating material 9 against heat losses, for example in the tool holder 13.
• thermocouples 10, 11, 12 in the immediate vicinity of the contact surfaces of Umformtechnikmaschinemaschinemaschine 1, 2, 3 ensures with the board that an accurate temperature of the corresponding areas of the board can be achieved.
• the drawing ring 1 and the blank holder 3 and the punch 2 with respect to the tool holder is thermally insulated, so that an uncontrolled heat flow into the tool holder 13 is prevented.
• the three temperature zones of the drawing ring 1, the punch 2 and the sheet-aged 3 can independently to different temperatures from room temperature to, for example, a maximum of 650 0 C, preferably 200 to 650 0 C, in particular from 400 0 C to 650 0 C, are set.
• temperature profiles in the forming tool can thus also be generated in order to be able to respond to corresponding Make the deformed board a structural change, for example, due to different cooling rates of the board in these areas, bring about.
• means for varying the surface pressure and the means for controlling the individual heating wires of the temperature zones are not shown in the single figure.
• the values for the yield strength R P0 , 2 dropped below 1000 MPa.
• the tensile strength values were less than 1500 MPa.
• the elongation at break A80 increased to about 5.8%.
• the tensile strength decreased from 820 MPa
• the cause of the changed strength values is seen in the fact that at higher forming tool temperature Austenitanteile continue to exist in the structure.
• a structure forming tool are therefore preferred, for example, 400 0 C to 650 ° C to achieve higher elongation at break values.
• the structure consists only of martensite and a maximum strength at reduced elongation at break is achieved.
• Exemplary embodiment of the forming tool according to the invention for press-hardening and tempered forming is particularly suitable for this purpose.
• Sample a) was formed in a temperature controlled at 410 0 C tool with a pressure of 80 bar and sample b) in a cooled to room temperature tool with a pressure of 80 bar.
• Sample a) had a bead of bainite with tempering effects. In contrast, in sample b) a martensitic, bainitic structure was detectable.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Heat Treatment Of Articles (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)
• Tires In General (AREA)
• Forging (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)
• Heat Treatment Of Steel (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Cited By (1)

Families Citing this family (34)

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• 2006
  • 2006-04-24 DE DE102006019395A patent/DE102006019395A1/de not_active Ceased
• 2007
  • 2007-04-24 MX MX2008013630A patent/MX2008013630A/es active IP Right Grant
  • 2007-04-24 ES ES07728442T patent/ES2333274T3/es active Active
  • 2007-04-24 BR BRPI0710175-9A patent/BRPI0710175A2/pt not_active IP Right Cessation
  • 2007-04-24 DE DE502007001501T patent/DE502007001501D1/de active Active
  • 2007-04-24 JP JP2009507060A patent/JP5270535B2/ja active Active
  • 2007-04-24 WO PCT/EP2007/053986 patent/WO2007122230A1/fr active Application Filing
  • 2007-04-24 CA CA2649519A patent/CA2649519C/fr active Active
  • 2007-04-24 PL PL07728442T patent/PL2012948T3/pl unknown
  • 2007-04-24 EP EP07728442A patent/EP2012948B1/fr active Active
  • 2007-04-24 AT AT07728442T patent/ATE442213T1/de active
  • 2007-04-24 US US12/297,543 patent/US9068239B2/en active Active
  • 2007-04-24 PT PT07728442T patent/PT2012948E/pt unknown

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