EP 4136265 A1 20230222 - METHOD FOR PRODUCING A STEEL STRIP WITH A MULTIPHASE STRUCTURE, AND RELATED STEEL STRIP
Title (en)
METHOD FOR PRODUCING A STEEL STRIP WITH A MULTIPHASE STRUCTURE, AND RELATED STEEL STRIP
Title (de)
VERFAHREN ZUR HERSTELLUNG EINES STAHLBANDES MIT EINEM MEHRPHASENGEFÜGE UND STAHLBAND HIERZU
Title (fr)
PROCÉDÉ DE FABRICATION D'UNE BANDE D'ACIER À STRUCTURE MULTIPHASÉE ET BANDE D'ACIER ASSOCIÉE
Publication
Application
Priority
- DE 102020110319 A 20200415
- EP 2021059672 W 20210414
Abstract (en)
[origin: WO2021209503A1] In order to provide a method which is intended for producing a steel strip with a multiphase structure and by which the production of complex geometries with a high energy-absorption capacity and high resistance to edge cracking is made possible, in particular compensating for the drop in yield strength, and consequently achieving a combination of a high yield strength or high yield-strength ratio and a high elongation at break, it is proposed that the method comprises the following steps: - producing a hot- or cold-rolled steel strip from a steel consisting of the following elements in % by weight: C: from 0.085 bis 0.149; Al: from 0.005 to 0.1; Si: from 0.2 to 0.75; Mn: 1.6 to 2.9; N: < 0.02; S: ≤ 0.005 and optionally of one or more of the following elements in % by weight: Cr: 0.05 to 0.5; Mo: 0.05 to 0.5; Ti: 0.005 to 0.060; Nb: 0.005 to 0.060; V: 0.001 to 0.060; B: 0.0001 to 0.0060; N: 0.0001 to 0.016; Ni: 0.01 to 0.5; Cu: 0.01 to 0.3; the remainder iron, including customary steel-accompanying elements, - first annealing, in particular continuous annealing, of the steel strip, in particular the cold-rolled steel strip, at a temperature of between 750°C and 950°C, inclusive, for the entire duration of 10 s to 1200 s, in particular from 50 s to 650 s, and subsequently first cooling of the steel strip to a temperature of between 200°C and 500°C, inclusive, at an average cooling rate of 2 K/s to 150 K/s, in particular of 5 K/s to 100 K/s, - further cooling of the steel strip to a supercooling temperature below 100°C at an average cooling rate of 1 K/s to 50 K/s, - final annealing, in particular continuous annealing, of the steel strip with a Hollomon-Jaffe parameter Hp = TH * (ln (Ʈ) +20) of > 7.5 x 103, where the maximum temperature TH in K is 100°C to 470°C, inclusive, and the total duration Ʈ in h is 2 s up to 1000 s, inclusive, and - final cooling of the steel strip to room temperature at an average cooling rate of 1 K/s to 160 K/s, in particular of 1 K/s to 30 K/s. The invention also relates to a steel strip with a multiphase structure, produced by this method.
IPC 8 full level
C21D 9/48 (2006.01); C21D 1/19 (2006.01); C21D 1/25 (2006.01); C21D 1/26 (2006.01); C21D 1/28 (2006.01); C21D 6/00 (2006.01); C21D 8/04 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/22 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01)
CPC (source: EP US)
C21D 1/19 (2013.01 - EP); C21D 1/25 (2013.01 - EP); C21D 1/26 (2013.01 - EP); C21D 1/28 (2013.01 - EP); C21D 6/005 (2013.01 - EP); C21D 6/008 (2013.01 - EP); C21D 8/0205 (2013.01 - US); C21D 8/0226 (2013.01 - US); C21D 8/0236 (2013.01 - US); C21D 8/0273 (2013.01 - US); C21D 8/0473 (2013.01 - EP); C21D 9/48 (2013.01 - EP); C21D 9/52 (2013.01 - US); C22C 38/02 (2013.01 - EP); C22C 38/04 (2013.01 - EP); C22C 38/06 (2013.01 - EP US); C22C 38/20 (2013.01 - US); C22C 38/22 (2013.01 - US); C22C 38/24 (2013.01 - US); C22C 38/26 (2013.01 - US); C22C 38/28 (2013.01 - US); C22C 38/38 (2013.01 - US); C21D 6/001 (2013.01 - EP); C21D 6/002 (2013.01 - EP); C21D 2211/001 (2013.01 - US); C21D 2211/002 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP US); C22C 38/22 (2013.01 - EP); C22C 38/26 (2013.01 - EP); C22C 38/28 (2013.01 - EP); C22C 38/32 (2013.01 - EP)
Citation (search report)
See references of WO 2021209503A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
Designated validation state (EPC)
KH MA MD TN
DOCDB simple family (publication)
DE 102020110319 A1 20211021; CN 115698347 A 20230203; EP 4136265 A1 20230222; US 2023077921 A1 20230316; WO 2021209503 A1 20211021
DOCDB simple family (application)
DE 102020110319 A 20200415; CN 202180040632 A 20210414; EP 2021059672 W 20210414; EP 21718871 A 20210414; US 202117918988 A 20210414