Global Patent Index - EP 3674426 B1

EP 3674426 B1 20220420 - METHOD FOR PRODUCTION OF NI-CONTAINING STEEL PLATE

Title (en)

METHOD FOR PRODUCTION OF NI-CONTAINING STEEL PLATE

Title (de)

VERFAHREN ZUR HERSTELLUNG VON NI-HALTIGEM STAHLBLECH

Title (fr)

PROCÉDÉ DE PRODUCTION DE TÔLE D'ACIER CONTENANT DU NI

Publication

EP 3674426 B1 20220420 (EN)

Application

EP 18848632 A 20180813

Priority

  • JP 2017162740 A 20170825
  • JP 2018131749 A 20180711
  • JP 2018030209 W 20180813

Abstract (en)

[origin: EP3674426A1] The method for production according to the embodiment of the present invention includes the steps of, in sequence: quenching a steel including a predetermined chemical composition, with the balance being Fe and inevitable impurities, from a quenching temperature of 800°C or higher and 820°C or lower after hot-rolling the steel; applying an intermediate heat treatment to the quenched steel by holding the steel at a heating temperature of 690°C or higher and 710°C or lower and then cooling the steel at an average cooling rate of 5°C/sec or more until a cooling end temperature of 200°C or lower; and tempering the steel at a tempering temperature of 570°C or higher and 600°C or lower, wherein a parameter H defined by a heating and holding time during the intermediate heat treatment, and a heating and holding time during the tempering is set at 1.73 × 10<sup>-6</sup>or more and 1.96 × 10<sup>-6</sup>or less.

IPC 8 full level

C21D 8/02 (2006.01); C21D 1/19 (2006.01); C21D 1/25 (2006.01); C21D 6/00 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/54 (2006.01)

CPC (source: EP KR)

C21D 1/18 (2013.01 - EP); C21D 1/185 (2013.01 - EP); C21D 1/19 (2013.01 - EP); C21D 1/25 (2013.01 - EP); C21D 6/001 (2013.01 - EP); C21D 6/005 (2013.01 - EP); C21D 8/0205 (2013.01 - KR); C21D 8/0226 (2013.01 - EP); C21D 8/0263 (2013.01 - EP); C21D 9/46 (2013.01 - EP); C22C 38/001 (2013.01 - EP); C22C 38/02 (2013.01 - EP); C22C 38/04 (2013.01 - EP); C22C 38/06 (2013.01 - EP); C22C 38/08 (2013.01 - EP KR); C22C 38/54 (2013.01 - KR); C21D 2211/005 (2013.01 - EP); C21D 2211/008 (2013.01 - EP)

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

DOCDB simple family (publication)

EP 3674426 A1 20200701; EP 3674426 A4 20201216; EP 3674426 B1 20220420; KR 102351770 B1 20220114; KR 20200033291 A 20200327; WO 2019039339 A1 20190228

DOCDB simple family (application)

EP 18848632 A 20180813; JP 2018030209 W 20180813; KR 20207004811 A 20180813