METHOD FOR THE OPTIMIZED PRODUCTION OF A COMPONENT WITH AT LEAST ONE ANCILLARY FORMED ELEMENT

Abstract

The invention relates to a method for the optimized production of a component, in particular from steel, with at least one secondary formed element, comprising the steps of a) providing a blank which has been cut to size at room temperature from a strip or a sheet and in which cut-outs and/or holes have optionally been created by stamping or cutting operations; b) thermal treatment of selected edge regions of the blank that have been cold-hardened by the stamping or cutting operations, in which the edge regions are heated to a temperature of at least 600 C. for a maximum 10 seconds; c) forming the thermally treated edge regions of the blank at ambient temperature to obtain a component with an unfinished secondary formed element; characterized by an additional step d), a calibrating step for obtaining the component with the secondary formed element, wherein the unfinished secondary formed element is formed at ambient temperature into a secondary formed element that has an increased and/or more uniform wall thickness in comparison with the unfinished secondary formed element.

Claims

1.-14. (canceled)

15. A method for the optimized production of a component, in particular of steel, with an ancillary formed element, comprising the steps of a) providing a blank cut from a strip or metal sheet at room temperature and optionally produced with recesses and/or openings by punching or cutting operations; b) temperature-treating selected edge regions of the blank that have been strain-hardened by the punching or cutting operations, by heating the edge regions to a temperature of at least 600 C. for a period of maximal 10 seconds; c) forming the temperature-treated edge regions of the blank at ambient temperature to obtain a component with raw ancillary formed element; and d) executing a calibration for obtaining the component with ancillary formed element by forming the raw ancillary formed element at ambient temperature into the ancillary formed element which has increased and/or homogenized wall thickness compared to the raw ancillary formed element.

16. The method of claim 15, wherein the ancillary formed element is a collar or a flange.

17. The method of claim 15, further comprising, prior to the temperature-treating step, forming selected edge regions of the blank that have been strain hardened by the punching or cutting operations at room temperature.

18. The method of claim 15, wherein the raw ancillary formed element is generated in step c) by forming the edge regions in a defined direction and wherein the formation of said edge regions in step d) is implemented in a direction opposite to the defined direction.

19. The method of claim 15, wherein the temperature-treating step is carried out for a period of 0.02 to 10 seconds.

20. The method of claim 15, wherein the temperature-treating step is carried out for a period of 0.1 to 2 seconds.

21. The method of claim 15, wherein the temperature-treating step is carried out at a temperature of 600 C. to a solidus temperature.

22. The method of claim 15, wherein the temperature-treating step is carried out at a temperature between a transformation temperature Ac1 and a solidus temperature.

23. The method of claim 15, wherein the edge regions are heated to the temperature of at least 600 C. Inductively, conductively, by radiation heating, or laser radiation.

24. The method of claim 15, further comprising coating the blank with an organic and/or metallic coating.

25. The method of claim 15, wherein the temperature-treating step of the edge regions, starting from an edge, takes place in a region which corresponds at most to a thickness of the blank.

26. The method of claim 15, further comprising flushing a region about a location of the temperature treatment during and optionally before and/or after the temperature-treating step with inert gas for protection against oxidation.

27. A component, in particular of steel, comprising an ancillary formed element with high and/or homogeneous wall thickness, wherein for the production of the component a blank is provided which is cut at room temperature from a strip or a sheet metal and in which recesses and/or openings are optionally produced by punching or cutting operations, wherein a temperature treatment of selected edge regions of the blank that have been strain hardened by the punching or cutting operations is carried out, with the edge portions being heated to a temperature of at least 600 C. for a period of maximal 10 seconds, wherein the temperature-treated edge regions of the blank was formed at room temperature to obtain a component with raw ancillary formed element, and wherein the raw ancillary formed element was formed to obtain the component with ancillary formed element at room temperature into an ancillary formed element of increased and/or homogenized wall thickness compared to the raw ancillary formed element.

28. The component of claim 27, wherein the ancillary formed element is a collar or a flange.

29. The component of claim 27, produced from a steel with the following alloy composition in wt.-%: TABLE-US-00002 C 0.01-0.2% Si .sup.0.2-4.0% Mn .sup.0.5-4.0% Al 0.02-0.1 Ti 0.0-0.2 V 0.0-0.3 Nb 0.0-0.1 with optional addition of Cr, Ni, Mo, B, balance iron, including impurities resulting from smelting.

30. A blank of steel for use in the production of a component with at least one ancillary formed element, wherein the blank previously cut at room temperature from a strip or a metal sheet is subjected, after undergoing punching or cutting operations at room temperature for realizing recesses or openings, in selected edge regions that were strain hardened by the punching or cutting operations to a temperature treatment in which the edge regions are heated of at least 600 C. for a period of a maximal 10 seconds, wherein the temperature treated edge regions of the blank are formed at room temperature to obtain a component with raw ancillary formed element, and wherein the raw ancillary formed element is formed at room temperature into an ancillary formed element having a wall thickness which is increased and/or homogenized compared to the raw ancillary formed element.

Description

[0048] In a modified embodiment, the method according to the invention includes between steps a) and b) not only the one additional forming step, but also any number of further consequences of the inventive temperature treatment of the edge regions at a temperature of at least 600 C. for a period of maximal 10 seconds and another forming step. In this way, it is possible to further form the material in each forming step, and to remove the interfering factors caused by the forming process, such as strain hardening, microstructure damages, and adverse contour changes such as, e.g. microcracks.

[0049] The individual forming and temperature treatment steps of the method according to the invention can be implemented at any time, i.e. temporally decoupled from one another.

[0050] The forming steps of the method according to the invention can advantageously be executed with forming tools, e.g. cylindrical or conical punches, that already exist in the production. As a result, no expensive investment costs for carrying out the method according to the invention are necessary.

[0051] The method according to the invention is particularly applicable to any shear-cut material edges, in particular to punched holes and edges with any contour. As a result of the increased formability in accordance with the invention, it becomes possible to also produce complex geometries that require, for example, several forming steps. Even complex components can be produced in one piece, eliminating the need for additional joining operations.

[0052] The temperature treatment is preferably carried out in the method according to the invention over the entire thickness of the blank and in plane direction of the blank in a region which corresponds at most to the thickness thereof. The duration of the temperature treatment depends on the type of heat treatment process.

[0053] Heating itself can be implemented in any desired manner, for example, conductively, inductively via radiation heating, or by laser processing. Especially suitable for temperature treatment is conductive heating, as used for example in the automotive industry in many cases as demonstrated by the example of spot welds.

[0054] Advantageously, the use of a spot welding machine for example with rather short treatment times for the treatment of punched holes in the blank is suitable, whereas at longer edge portions to be treated, the inductive method, radiation heating or laser processing with longer treatment times are considered.

[0055] Thus, the heat input is very concentrated into the shear-affected cutting edge regions and is therefore accompanied with a comparatively little energy consumption, in particular with regard to processes in which the entire blank is subjected to a heating or which find application in a stress relief heat treatment that is more time consuming by orders of magnitude.

[0056] According to one embodiment of the method of the invention, the blank has a metallic and/or organic coating. This coating may contain or be made of zinc, magnesium, aluminum and/or silicon. The blank itself can e.g. be rolled flexibly with different thicknesses or be joined from cold or hot strip of same or different thickness and/or quality. The invention is applicable to hot or cold rolled steel strips of soft to high strength steels.

[0057] As higher strength steels, all single-phase as well as multi-phase steel grades find application. These include micro-alloyed, higher strength steel grades as well as bainitic, ferritic or martensitic grades as well as dual phases, complex phases and TRIP steels.

[0058] According to a possible embodiment of the method, to protect against oxidation during and optionally before and/or after the temperature treatment, the region around the location of the temperature treatment can be flushed by an inert gas.

[0059] In view of the short temperature treatment period of maximal 10 seconds, the method according to the invention can be integrated as an intermediate operating step in a series production which specifies a clock rate in the range of 0.1 to 10 seconds. In particular, the production of sheet metal components in the automotive sector in several successive steps thus represents a predestined field of application of the method according to the invention.

[0060] The invention also relates to a component having at least one ancillary formed element with high and/or homogeneous wall thickness, wherein for the production of the component a blank is provided which has been cut at room temperature from a strip or sheet metal and has been optionally produced by punching or cutting operations with recesses and/or openings, wherein a temperature treatment of selected edge regions of the blank that have been strain hardened by the punching or cutting operations is carried out, with the edge portions being heated to a temperature of at least 600 C. for a period of maximal 10 seconds, wherein the temperature-treated edge regions of the blank were formed at room temperature to obtain a component with raw ancillary formed element, and wherein the raw ancillary formed element was formed to obtain the component with ancillary formed element at room temperature into an ancillary formed element of increased and/or homogenized wall thickness compared to the raw ancillary formed element.

[0061] In an advantageous refinement of the invention, it is provided that the formed edge regions are repeatedly heat-treated and reshaped.

[0062] Preferred components are e.g. chassis components of hot sheet or cold sheet with attached ancillary formed elements, in particular collar, flanges and/or edges, which are obtainable by a method according to the invention.

[0063] Finally, the invention also relates to the use of a blank of steel for producing a component with at least one ancillary formed element, wherein the blank previously cut at room temperature from a strip or a metal sheet is subjected after optional further manufacturing steps are carried out at room temperature, such as e.g. punching or cutting operations for realizing recesses or openings, in selected edge regions that were strain hardened by the punching or cutting operations to a temperature treatment in which the edge regions are heated of at least 600 C. for a period of a maximal 10 seconds, wherein the temperature-treated edge regions of the blank are formed at room temperature to obtain a component with raw ancillary formed element, and wherein the raw ancillary formed element is formed at room temperature into an ancillary formed element having a wall thickness which is increased and/or homogenized compared to the raw ancillary formed element. In an advantageous refinement of the invention, it is provided that here too the formed edge regions are repeatedly heat-treated and reshaped.

[0064] The features of the invention as disclosed in the above description and in the claims may be essential individually as well as in any desired combinations for the realization of the invention in its various embodiments.