公开(公告)号：US20180010220A1

公开(公告)日：2018-01-11

申请号：US15711335

申请日：2017-09-21

Applicant: ARCELORMITTAL

Inventor： Sebastien Allain ,  Audrey Couturier ,  Thierry Iung ,  Christine Colin

IPC: C22C38/02 ,  C22C38/34 ,  C22C38/22 ,  C22C38/12 ,  C21D9/32 ,  C21D1/19 ,  C22C38/04 ,  C21D8/02 ,  C21D9/46 ,  C22C38/38 ,  C22C38/06

CPC classification number: C22C38/02 ,  C21D1/19 ,  C21D8/02 ,  C21D9/32 ,  C21D9/46 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/22 ,  C22C38/34 ,  C22C38/38

Abstract: The invention relates to a hot-rolled steel sheet having a tensile strength of greater than 1200 MPa, an Re/Rm ratio of less than 0.75 and an elongation at break of greater than 10%, the composition of which contains, the contents being expressed by weight: 0.10%≦C≦0.25%; 1%≦Mn≦3%; Al≧0.015%; Si≦1.985%; Mo≦0.30%; Cr≦1.5%; S≦0.015%; P≦0.1%; Co≦1.5%; B≦0.005%; it being understood that 1%≦Si+Al≦2%; Cr +(3×Mo)≦0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel consisting of at least 75% bainite, residual austenite in an amount equal to or greater than 5% and martensite in an amount equal to or greater than 2%.

公开(公告)号：US12188102B2

公开(公告)日：2025-01-07

申请号：US16302988

申请日：2017-05-23

Applicant: ARCELORMITTAL

Inventor： Jean-Christophe Hell ,  Nicolas Charbonnier ,  Thierry Iung ,  Blandine Remy

IPC: C22C30/00 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/16 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/58

Abstract: A method for manufacturing a recovered steel sheet having an austenitic matrix presenting at least one mechanical property (M) equal or above a target value Mtarget is provided. The method includes a calibrating process involving heat treatments on at least 2 samples of the steel, corresponding to Pareq values P, submitting said samples to X-ray diffraction so as to obtain spectrums including a main peak whose width at mid height FWHM is being measured, measuring a mechanical property (M) of said samples, measuring a recovery or recrystallization state of each sample, drawing a curve of M as a function of FWMH in a domain where the samples are recovered from 0 to 100%, but not recrystallized. The method further includes calculating a FWHMtarget corresponding to a target mechanical property Mtarget, determining a pareq value Ptarget of the heat treatment to perform to reach Mtarget and selecting a time ttarget and a temperature T°target corresponding to the Ptarget value. The method further includes feeding a recrystallized steel sheet having a Mrecrystallization, cold-rolling the recrystallized steel sheet in order to obtain a steel sheet having a Mcold-roll and annealing the cold rolled steel sheet at a temperature T°target during a time ttarget.

公开(公告)号：US10995381B2

公开(公告)日：2021-05-04

申请号：US16302974

申请日：2017-05-22

Applicant: ARCELORMITTAL

Inventor： Thierry Iung ,  Gerard Petitgand

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/16 ,  C22C38/20 ,  C22C38/24 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40 ,  C21D1/26 ,  C21D8/02 ,  C21D6/00 ,  C21D8/04

Abstract: A method for the manufacture of a cold rolled, recovered TWIP steel sheet coated with a metallic coating is provided including the following steps: (A) the feeding of a slab having the following composition: 0.1

公开(公告)号：US10370746B2

公开(公告)日：2019-08-06

申请号：US15711335

申请日：2017-09-21

Applicant: ARCELORMITTAL

Inventor： Sebastien Allain ,  Audrey Couturier ,  Thierry Iung ,  Christine Colin

IPC: C21D1/19 ,  C22C38/02 ,  C21D8/02 ,  C21D9/32 ,  C21D9/46 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/22 ,  C22C38/34 ,  C22C38/38

Abstract: The invention relates to a hot-rolled steel sheet having a tensile strength of greater than 1200 MPa, an Re/Rm ratio of less than 0.75 and an elongation at break of greater than 10%, the composition of which contains, the contents being expressed by weight: 0.10%≤C≤0.25%; 1%≤Mn≤3%; Al≥0.015%; Si≤1.985%; Mo≤0.30%; Cr≤1.5%; S≤0.015%; P≤0.1%; Co≤1.5%; B≤0.005%; it being understood that 1%≤Si+Al≤2%; Cr+(3×Mo)≥0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel consisting of at least 75% bainite, residual austenite in an amount equal to or greater than 5% and martensite in an amount equal to or greater than 2%.