US20210189513A1 - Method and device for producing hardened steel components - Google Patents

Method and device for producing hardened steel components Download PDF

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Publication number
US20210189513A1
US20210189513A1 US16/074,303 US201716074303A US2021189513A1 US 20210189513 A1 US20210189513 A1 US 20210189513A1 US 201716074303 A US201716074303 A US 201716074303A US 2021189513 A1 US2021189513 A1 US 2021189513A1
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United States
Prior art keywords
oxygen
forming
inserts
forming tool
hardening
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.)
Abandoned
Application number
US16/074,303
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English (en)
Inventor
Johannes Haslmayr
Siegfried Kolnberger
Harald Schwinghammer
Andreas Sommer
Benedikt Tutewohl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Voestalpine Stahl GmbH
Voestalpine Metal Forming GmbH
Original Assignee
Voestalpine Stahl GmbH
Voestalpine Metal Forming GmbH
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 Voestalpine Stahl GmbH, Voestalpine Metal Forming GmbH filed Critical Voestalpine Stahl GmbH
Assigned to VOESTALPINE STAHL GMBH, VOESTALPINE METAL FORMING GMBH reassignment VOESTALPINE STAHL GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HASLMAYR, Johannes, SCHWINGHAMMER, HARALD, TUTEWOHL, Benedikt, SOMMER, ANDREAS, KOLNBERGER, SIEGFRIED
Publication of US20210189513A1 publication Critical patent/US20210189513A1/en
Abandoned legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0062—Heat-treating apparatus with a cooling or quenching zone
    • 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
    • B21D22/208—Deep-drawing by heating the blank or deep-drawing 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
    • B21D28/00—Shaping by press-cutting; Perforating
    • B21D28/24—Perforating, i.e. punching holes
    • B21D28/26—Perforating, i.e. punching holes in sheets or flat parts
    • 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
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/613—Gases; Liquefied or solidified normally gaseous material
    • 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

Definitions

  • the invention relates to a method and device for producing hardened steel components.
  • Hardened steel components particularly in vehicle body construction for motor vehicles, have the advantage that due to their outstanding mechanical properties, it is possible to achieve a particularly stable passenger compartment without having to use components that are much more massive at normal strengths and must therefore be embodied as much heavier.
  • steel types that can be hardened by means of a quench hardening.
  • Steel types of this kind include, for example, boron-alloyed manganese carbon steels, the most widely-used steel being 22MnB5. But other boron-alloyed manganese carbon steels are also used for this purpose.
  • the steel material In order to produce hardened components from these types of steel, the steel material must be heated to the austenitization temperature (>Ac 3 ) and it is necessary to wait until the steel material is austenitized. Depending on the desired degree of hardness, partial or complete austenitization can be achieved in this connection.
  • a sheet steel blank is cut out from a steel band and then—using a conventional, for example five-step, deep drawing process—is deep drawn to produce the finished component.
  • This finished component in this case is dimensioned somewhat smaller in order to compensate for a subsequent thermal expansion during the austenitization.
  • the component produced in this way is austenitized and then inserted into a form hardening tool in which it is pressed, but is not formed or is only formed to a very slight extent and by means of the pressing, the heat flows out of the component and into the press tool, specifically at the speed greater than the critical hardening speed.
  • press hardening in which a blank is cut out from a sheet steel band, then the blank is austenitized and the hot blank is formed in a one-stage step and at the same time, is cooled at a speed greater than the critical hardening speed.
  • the advantage of the direct method is that a higher material utilization ratio can be achieved, but with a lower component complexity.
  • First-order microcracks are attributed to so-called liquid metal embrittlement.
  • the theory is that during the forming, i.e. as tensile stresses are being exerted on the material, liquid zinc phases interact with still existing austenite phases, causing microcracks with depths of up to a few hundred ⁇ m to be produced in the material.
  • the applicant has succeeded in suppressing this by cooling the material—in the time between the removal from the heating furnace and the insertion into the forming tool—to temperatures at which liquid zinc phases are no longer present. This means that the hot-forming takes place at temperatures below approximately 750° C.
  • DE 10 2011 055 643 A1 has disclosed a method and a forming tool for hot-form press hardening components made of sheet steel, particularly made of galvanized workpieces composed of sheet steel.
  • the material that is applied to the surface of the drawing edge region facing the workpiece or of the insert piece that has been put into position should have a transverse dimension extending across the drawing edge that is in a range of 1.6 to 10 times the positive drawing radius of the female die. This should improve the flow properties of workpieces made of sheet steel during the hot-forming and should thus significantly reduce the risk of the occurrence of cracks in the hot-forming of workpieces made of sheet steel, preferably made of galvanized steel blanks. Such a tool, however, does not make it possible to avoid microcracks of the second type.
  • DE 10 2011 052 773 A1 has disclosed a tool for a press hardening tool in which the mold surface of the tool is microstructured in some regions by two micro-cavities that are introduced into the mold surface. This step is intended to four restrict the effective contact area for the forming of a blank between the mold surface with a blank to the surface portions situated between the cavities. This is intended to reduce the friction.
  • DE 10 2004 038 626 B3 has disclosed a method for producing hardened components out of sheet steel in which before or after the forming of the formed part, a required final trimming of the formed part and any necessary punching procedures or the production of a hole pattern is carried out and the formed part is then heated at least in some areas to a temperature that enables an austenitization of the steel material; the component is then transferred to a form hardening tool and a form hardening is carried out in the form hardening tool in which the component is cooled and thus hardened at least in some areas by the contact and pressing of the component; and the component is supported by the form hardening tool, at least in some areas, in the region of the positive radii and is preferably held by two clamps in the region of the trim edges and in regions in which the component is not clamped, the component is at least spaced apart from a mold half by means of a gap.
  • This measure makes it possible to clamp the component in a distortion-free manner and to set different hardness gradients by means of different hard
  • the object of the invention is to avoid microcracks of the second type in directly hot-formed, i.e. press hardened, components.
  • the object is attained with a method having the features of claim 1 .
  • Another object of the invention is to create a device with which sheet steel blanks can be hot-formed and hardened in the press hardening process and in which microcracks are avoided.
  • microcracks of the second type are produced when, in regions under tensile strain, the zinc vapor that occurs arrives at the steel in a sufficient concentration, so-called vapor metal embrittlement (VME).
  • VME vapor metal embrittlement
  • Zinc vapor is produced due to the tearing of the zinc/iron layer that occurs in the stretching during the forming process.
  • a sufficient concentration particularly occurs in those regions in which direct contact of the sheet metal with the tool prevails or the sheet metal is a very small distance from the tool.
  • a very small distance as defined by the invention is being less than 0.5 mm.
  • second-order microcracks should be avoided, while retaining the largest possible working window with regard to the material and temperature and ensuring an inexpensive implementation. With at least the same residence time, there should be no increase in cycle time or reduction in throughput during component production.
  • the zinc vapor or free zinc that occurs is quickly transformed into a stable compound such as zinc oxide or ZnI 2 .
  • the protection of the steel from second-order microcracks can also be achieved by producing a protective layer such as an oxide layer by supplying a fluid. The measures described above have demonstrated that microcracks are significantly reduced.
  • Gaseous oxygen-containing fluids such as air or oxygen are particularly preferable because they cannot excessively contaminate the tool and in addition, a possibly unwanted massive cooling action of the kind that can occur, for example, by means of water can be more easily regulated by tempering the fluid.
  • inserts are used, which permit an entry of oxygen when the sheet metal blank is being deformed, i.e. when the blank material is flowing.
  • inserts can also be provided at narrow points or contact regions of the sheet metal blank with the tool, these contact regions being defined as the regions in which the distance of the sheet metal to the tool is at most 0.5 mm.
  • the corresponding material naturally has to be supported in the region of the positive radii because these are the edges that produce the deformation and initiate the flow of material.
  • the inserts Adjacent to these edges and spaced apart from them so that the inserts are not damaged, the inserts have means that enable an entry of oxygen.
  • These means can, for example, be sintered metal inserts or porous ceramic inserts in which, after the move away from each other and the workpiece hardens and before a new blank is inserted, enough oxygen is stored that it can be imparted to released zinc or released zinc phases.
  • the inserts have surfaces that are left open so that the material, after it has flowed past the edge, is spaced apart from the insert.
  • this left-open region is embodied as slotted so that a minimum support of the material is possible, but the entry of oxygen is ensured.
  • fluid connection lines which feed into the open regions or into the regions that that are filled with sintered metal or porous ceramic so that a sufficient amount of oxygen is supplied.
  • this can be air or also water vapor, for example.
  • Materials that inherently have a high oxygen diffusion capacity such as certain ceramics can also be embodied in a massive form and are acted on with oxygen-containing fluids either while the press is open or from the rear and store this oxygen until it can be imparted to released zinc iron phases or released zinc.
  • inserts can be embodied on both the female die and the male die.
  • a charging with oxygen can also be carried out by flooding the mold cavity, for example with water vapor or with the mediums already mentioned above.
  • FIG. 1 shows an example of a tool insert in a massive embodiment
  • FIG. 2 shows a tool insert with a recess
  • FIG. 3 shows another tool insert with a recess
  • FIG. 4 is a sectional side view of a slotted tool insert
  • FIG. 5 shows the slotted tool insert in a view from the forming surface.
  • an insert 1 is made of a ceramic and in particular, of an oxide ceramic.
  • the ceramic insert extends along drawing edges 2 and is used in the tool in lieu of the metallic drawing edge 2 ; it has a back side 3 and an underside 4 with which it is inserted in a form-fitting way into a recess in the metallic tool.
  • the ceramic insert 1 has a top side 6 and mold-front side 5 , the mold-front side 5 and top side 6 preferably being flush with the corresponding surfaces of the tool.
  • This ceramic insert can be embodied as massive or impervious and hard or porous and hard.
  • a gas connection (not shown) can be provided, if the ceramic is embodied as oxygen-conducting or porous, which brings a sufficient concentration of oxygen through the insert 1 to the region of the surfaces 5 and the drawing edge 2 .
  • a recess 7 is produced in the region of the surface 5 adjacent to the drawing edge 2 .
  • the recess 7 has a depth of 5 to 10 mm, whereas the insert as a whole has a height between the surfaces 4 and 6 of 35 to 50 mm and a width between the surfaces 3 and 5 of 15 to 30 mm, for example.
  • the drawing edge 2 in this case is embodied so that the thickness of the drawing edge in front of the recess 7 corresponds approximately to its radius.
  • such a groove 8 with these dimensions stores enough oxygen in the form of a gas after the demolding of a component and the insertion of a new blank to ensure the sufficient oxygen supply during the forming.
  • the surface 5 is embodied with slots 9 , which extend from a surface 4 in the direction of the drawing edge 2 , but the drawing edge 2 still has a thickness that corresponds to its radius.
  • the slot width in this case is 4 to 8 mm, with a slot spacing of 7 to 11 mm so that a bridge piece width of 2 to 5 mm is achieved with a slot depth of 5 to 9 mm.
  • the bridge piece width does not negatively influence the oxygen supply.
  • the recesses 7 or the groove 8 or the slots 9 are filled with a porous ceramic material or a porous sintered metal material; on the back side 3 of the insert, supply openings for oxygen-containing fluids can be provided and/or the sintered metal inserts or ceramic inserts are charged with oxygen between the forming procedures, for example by flooding the mold cavity with water vapor, or the ceramic and/or the sintered metal has a high enough oxygen affinity that during the forming procedures, oxygen is absorbed, which during the drawing procedure, is imparted to released zinc iron or zinc phases.
  • the invention has the advantage that relatively simple measures can be used to effectively prevent the formation of second-order microcracks; also, existing forming tools can be retrofitted by milling out the positive radius regions and/or the drawing edges inserting correspondingly shaped inserts.
  • the mold cavity can also be flushed with an oxygen-containing fluid so that at all times, there is a sufficient oxygen reservoir in the recesses 5 , grooves 6 , and slots 7 .
  • 20MnB8, 22MnB8, and other manganese/boron steels are also used in addition to 22MnB5.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Heat Treatment Of Articles (AREA)
  • Mounting, Exchange, And Manufacturing Of Dies (AREA)
US16/074,303 2016-02-10 2017-02-07 Method and device for producing hardened steel components Abandoned US20210189513A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102016102324.8A DE102016102324B4 (de) 2016-02-10 2016-02-10 Verfahren und Vorrichtung zum Erzeugen gehärteter Stahlbauteile
DE102016102324.8 2016-02-10
PCT/EP2017/052604 WO2017137378A1 (de) 2016-02-10 2017-02-07 Verfahren und vorrichtung zum erzeugen gehärteter stahlbauteile

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US20210189513A1 true US20210189513A1 (en) 2021-06-24

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US16/074,303 Abandoned US20210189513A1 (en) 2016-02-10 2017-02-07 Method and device for producing hardened steel components

Country Status (8)

Country Link
US (1) US20210189513A1 (ja)
EP (1) EP3414027B1 (ja)
JP (1) JP6753939B2 (ja)
KR (1) KR20180113559A (ja)
CN (1) CN109070174B (ja)
DE (1) DE102016102324B4 (ja)
ES (1) ES2792080T3 (ja)
WO (1) WO2017137378A1 (ja)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3962673A1 (en) * 2019-04-29 2022-03-09 Autotech Engineering S.L. A hot press forming apparatus and a method for hot press forming a blank

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD34665A (ja) *
DE10000138A1 (de) * 2000-01-04 2001-07-12 Binder Technologie Ag Gams Verfahren und Vorrichtung zur Herstellung von Formteilen
EP1651789B1 (de) * 2003-07-29 2010-08-25 Voestalpine Stahl GmbH Verfahren zum herstellen von geharteten bauteilen aus stahlblech
AT412878B (de) * 2003-07-29 2005-08-25 Voestalpine Stahl Gmbh Korrosionsgeschütztes stahlblechteil mit hoher festigkeit
DE102004038626B3 (de) * 2004-08-09 2006-02-02 Voestalpine Motion Gmbh Verfahren zum Herstellen von gehärteten Bauteilen aus Stahlblech
JP2006104527A (ja) * 2004-10-06 2006-04-20 Nippon Steel Corp 高強度部品の製造方法と高強度部品
JP2007216257A (ja) * 2006-02-16 2007-08-30 Toyota Motor Corp 高強度部品製造方法、高強度部品製造方法に用いられる熱間プレス成形型及び高強度部品製造方法における中間成形品
DE102007061489A1 (de) * 2007-12-20 2009-06-25 Voestalpine Stahl Gmbh Verfahren zum Herstellen von gehärteten Bauteilen aus härtbarem Stahl und härtbares Stahlband hierfür
DE102008063985B4 (de) * 2008-12-19 2015-10-29 Voestalpine Metal Forming Gmbh Verfahren und Vorrichtung zum Erzeugen partiell gehärteter Stahlblechbauteile
JP5515304B2 (ja) * 2009-01-30 2014-06-11 新日鐵住金株式会社 鋼板の熱間プレス成形方法及び熱間プレス成形装置
CN102782188B (zh) * 2009-12-28 2014-06-18 新日铁住金株式会社 热压成形构件的制造方法
JP5695381B2 (ja) * 2010-09-30 2015-04-01 株式会社神戸製鋼所 プレス成形品の製造方法
HUE052381T2 (hu) * 2010-12-24 2021-04-28 Voestalpine Stahl Gmbh Módszer edzett szerkezeti elemek elõállítására
DE102011052773A1 (de) * 2011-08-17 2013-02-21 Kirchhoff Automotive Deutschland Gmbh Werkzeug für ein Presshärtwerkzeug
CN102430628A (zh) * 2011-09-30 2012-05-02 大连理工大学 一种多层金属复合板材的热成形方法
DE102011055643A1 (de) * 2011-11-23 2013-05-23 Thyssenkrupp Steel Europe Ag Verfahren und Umformwerkzeug zum Warmumformen und Presshärten von Werkstücken aus Stahlblech, insbesondere verzinkten Werkstücken aus Stahlblech
JP6075304B2 (ja) * 2013-03-28 2017-02-08 株式会社豊田中央研究所 熱間プレス成形方法および熱間プレス成形装置
DE102013108044B3 (de) * 2013-07-26 2014-11-20 Voestalpine Metal Forming Gmbh Kühlkörper mit Abstandhalter
DE102013015405A1 (de) * 2013-09-17 2014-05-08 Daimler Ag Vorrichtung und Verfahren zum Presshärten eines Blechs
DE102014101159B4 (de) * 2014-01-30 2016-12-01 Thyssenkrupp Steel Europe Ag Verfahren zur Oberflächenbehandlung von Werkstücken

Also Published As

Publication number Publication date
EP3414027A1 (de) 2018-12-19
WO2017137378A1 (de) 2017-08-17
KR20180113559A (ko) 2018-10-16
DE102016102324B4 (de) 2020-09-17
JP2019508252A (ja) 2019-03-28
DE102016102324A1 (de) 2017-08-10
JP6753939B2 (ja) 2020-09-09
CN109070174A (zh) 2018-12-21
CN109070174B (zh) 2021-05-04
EP3414027B1 (de) 2020-05-06
ES2792080T3 (es) 2020-11-10

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