Method for producing a hot-formed steel component, and hot formed steel component

Abstract

The invention relates to a method for producing a component by hot-forming a pre-product composed of steel, wherein the pre-product is heated to a temperature above 60° C. and below the Ac3 transformation temperature and then formed in this temperature range, wherein the component has a minimum tensile strength of 700 MPa and high elongation at break, wherein the pre-product has the following alloy composition in percent by weight: C: 0.0005 to 0.9; Mn: more than 3.0 to 12; the remainder iron including unavoidable steel-accompanying elements, with the optional addition of one or more of the following elements (in percent by weight): Al: up to 10; Si: up to 6; Cr: up to 6; Nb: up to 1.5; V; up to 1.5; Ti: up to 1.5; Mo: up to 3; Cu: up to 3; Sn: up to 0.5; W up to 5; Co: up to 8; Zr: up to 0.5; Ta: up to 0.5; Te: up to 0.5; B: up to 0.15; P: at most 0.1, in particular <0.04; S: at most 0.1, in particular <0.02; N: at most 0.1, in particular <0.05; Ca: up to 0.1. The invention further relates to a hot-formed component produced from a steel.

What is claimed is: 
     
         1 .- 38 . (canceled) 
     
     
         39 . A method for producing a component with a minimum tensile strength of 700 MPa and high elongation at fracture A80 in %, said method comprising:
 heating a pre-product of steel to a temperature in a temperature range above 60° C. and below 450° C., with the pre-product having a following steel composition in wt. %:   C: 0.0005 to 0.9   Mn: more than 3.0 to 12,   with the remainder being iron including unavoidable steel-associated elements; and   hot-forming the pre-product in said temperature range,   wherein a residual austenite proportion is 5% to 80%.   
     
     
         40 . The method of  claim 39 , wherein the pre-product includes at least one alloying element selected from the group consisting of (in wt. %):
 Al: up to 10   Si: up to 6   Cr: up to 6   Nb: up to 1.5   V: up to 1.5   Ti: up to 1.5   Mo: up to 3   Cu: up to 3   Sn: up to 0.5   W: up to 5   Co: up to 8   Zr: up to 0.5   Ta: up to 0.5   Te: up to 0.5   B: up to 0.15   P: max. 0.1, in particular <0.04   S: max. 0.1, in particular <0.02   N: max. 0.1, in particular <0.05   Ca: up to 0.1.   
     
     
         41 . The method of  claim 39 , wherein the steel contains (in wt. %) C: 0.05 to 0.42. 
     
     
         42 . The method of  claim 39 , wherein the steel contains (in wt. %) Mn: >5 to <10. 
     
     
         43 . The method of  claim 39 , wherein the steel contains (in wt. %) Al: 0.1 to 5, in particular >0.5 to 3. 
     
     
         44 . The method of  claim 39 , wherein the steel contains (in wt. %) Si: 0.05 to 3, in particular >0.1 to 1.5. 
     
     
         45 . The method of  claim 39 , wherein the steel contains (in wt. %) Cr: 0.1 to 4, in particular >0.5 to 2.5. 
     
     
         46 . The method of  claim 39 , wherein the steel contains (in wt. %) Nb: 0.005 to 0.4, in particular 0.01 to 0.1. 
     
     
         47 . The method of  claim 39 , wherein the steel contains (in wt. %) V: 0.005 to 0.6, in particular 0.01 to 0.3. 
     
     
         48 . The method of  claim 39 , wherein the steel contains (in wt. %) Ti: 0.005 to 0.6, in particular 0.01 to 0.3. 
     
     
         49 . The method of  claim 39 , wherein the steel contains (in wt. %) Mo: 0.005 to 1.5, in particular 0.01 to 0.6. 
     
     
         50 . The method of  claim 39 , wherein the steel contains (in wt. %) Sn: <0.2, in particular <0.05. 
     
     
         51 . The method of  claim 39 , wherein the steel contains (in wt. %) Cu: <0.5, in particular <0.1. 
     
     
         52 . The method of  claim 39 , wherein the steel contains (in wt. %) W: 0.01 to 3, in particular 0.2 to 1.5. 
     
     
         53 . The method of  claim 39 , wherein the steel contains (in wt. %) Co: 0.01 to 5, in particular 0.3 to 2. 
     
     
         54 . The method of  claim 39 , wherein the steel contains (in wt. %) Zr: 0.005 to 0.3, in particular 0.01 to 0.2. 
     
     
         55 . The method of  claim 39 , wherein the steel contains (in wt. %) Ta: 0.005 to 0.3, in particular 0.01 to 0.1. 
     
     
         56 . The method of  claim 39 , wherein the steel contains (in wt. %) Te: 0.005 to 0.3, in particular 0.01 to 0.1. 
     
     
         57 . The method of  claim 39 , wherein the steel contains (in wt. %) B: 0.001 to 0.08, in particular 0.002 to 0.01. 
     
     
         58 . The method of  claim 39 , wherein the steel contains (in wt. %) Ca: 0.005 to 0.1. 
     
     
         59 . The method of  claim 39 , wherein the pre-product is heated only partially at a temperature range of above 60° C. to below 450° C. 
     
     
         60 . The method of  claim 39 , wherein the pre-product is heated to a temperature of below 700° C. 
     
     
         61 . The method of  claim 39 , wherein the temperature range in which the pre-product is heated ranges from 450 to below 700° C. 
     
     
         62 . The method of  claim 39 , wherein the temperature range in which the pre-product is heated ranges from 350 to below 450° C. 
     
     
         63 . The method of  claim 39 , wherein the temperature range in which the pre-product is heated ranges from 60 to below 350° C. 
     
     
         64 . The method of  claim 39 , further comprising applying a metallic or lacquer-like coat on the pre-product prior to the pre-product being heated. 
     
     
         65 . The method of  claim 64 , wherein the metallic coat contains at least one element selected from the group consisting of Zn, Mg, Al and Si. 
     
     
         66 . The method of  claim 64 , wherein the metallic coat contains a Zn alloy selected from the group consisting of ZnMg, ZnAl, ZnNi, ZnFe, ZnCo or ZnAlCe. 
     
     
         67 . The method of  claim 39 , wherein the pre-product is heated to the temperature inductively, conductively, by radiation, or by heat conduction in a forming tool and further comprising cooling the pre-product, after forming, in air or in a technically accelerated manner by means of moving gases, air or liquid media in or outside the forming tool. 
     
     
         68 . The method of  claim 39 , wherein the pre-product is a sheet metal plate or a pipe. 
     
     
         69 . The method of  claim 68 , wherein the sheet metal plate is made of a hot strip or cold strip. 
     
     
         70 . The method of  claim 68 , wherein the pipe is a seamlessly hot-rolled pipe or a welded pipe which is produced from hot strip or cold strip, and further comprising coating the pipe with an inner coating and/or outer coating. 
     
     
         71 . The method of  claim 68 , wherein the pipe is a seamlessly hot-rolled pipe or a welded pipe which is produced from a hot strip or cold strip and which, in the course of the hot-forming procedure, is subjected to one or multiple drawing and/or annealing processes. 
     
     
         72 . The method of  claim 39 , further comprising subjecting the pre-product after hot-forming to final cold-forming. 
     
     
         73 . A hot-formed component, produced from a steel comprising an alloy composition in wt. %:
 C: 0.0005 to 0.9   Mn: more than 3.0 to 12   with the remainder being iron including unavoidable steel-associated elements, with optional addition by alloying of one or more of the following elements (in wt. %):   Al: up to 10   Si: up to 6   Cr: up to 6   Nb: up to 1.5   V: up to 1.5   Ti: up to 1.5   Mo: up to 3   Cu: up to 3   Sn: up to 0.5   W: up to 5   Co: up to 8   Zr: up to 0.5   Ta: up to 0.5   Te: up to 0.5   B: up to 0.15   P: max. 0.1, in particular <0.04   S: max. 0.1, in particular <0.02   N: max. 0.1, in particular <0.05   Ca: up to 0.1.   by hot-forming a pre-product of said steel, in which the pre-product is heated to a temperature of 60° C. to below the Ac 3  conversion temperature and is then formed, wherein the component has a minimum tensile strength of 700 MPa to over 1350 MPa with a simultaneously high elongation at fracture A80 and the product of tensile strength x elongation at fracture has at least the following values:   Rm of 700 to 800 MPa: Rm×A80≥15400 up to 50000   Rm of over 800 to 900 MPa: Rm×A80≥14400 up to 50000   Rm of over 900 to 1100 MPa: Rm×A80≥13500 up to 45000   Rm of over 1100 to 1200 MPa: Rm×A80≥13200 up to 45000   Rm of over 1200 to 1350 MPa: Rm×A80≥11200 up to 45000   Rm of over 1350 to 1800 MPa: Rm×A80≥8000 up to 45000   Rm of over 1800 MPa: Rm×A80≥4000 up to 30000.   
     
     
         74 . The hot-formed component of  claim 73 , comprising an alloy composition in wt. %:
 C: 0.05 to 0.42   Mn: >5 to <10   with the remainder being iron including unavoidable steel-associated elements, with optional addition by alloying of one or more of the following elements (in wt. %):   Al: 0.1 to 5, in particular >0.5 to 3   Si: 0.05 to 3, in particular >0.1 to 1.5   Cr: 0.1 to 4, in particular >0.5 to 2.5   Nb: 0.005 to 0.4, in particular 0.01 to 0.1   B: 0.001 to 0.08, in particular 0.002 to 0.01   Ti: 0.005 to 0.6, in particular 0.01 to 0.3   Mo: 0.005 to 1.5, in particular 0.01 to 0.6   Sn: <0.2, in particular <0.05   Cu: <0.5, in particular <0.1   W: 0.01 to 3, in particular 0.2 to 1.5   Co: 0.01 to 5, in particular 0.3 to 2   Zr: 0.005 to 0.3, in particular 0.01 to 0.2   Ta: 0.005 to 0.3, in particular 0.01 to 0.1   Te: 0.005 to 0.3, in particular 0.01 to 0.1   V: 0.005 to 0.6, in particular 0.01 to 0.3   Ca: 0.0005 to 0.1.   
     
     
         75 . The hot-formed component of  claim 73 , produced by a method as set forth in  claim 59 . 
     
     
         76 . The hot-formed component of  claim 75 , for use in the automotive and commercial vehicle industries, in engineering, construction or for producing white goods.