US 11,932,916 B2
Method of dynamical adjustment for manufacturing a thermally treated steel sheet
Frédéric Bonnet, Avril (FR); and Van Thang Pham, Metz (FR)
Assigned to ArcelorMittal, Luxembourg (LU)
Appl. No. 16/466,742
Filed by ArcelorMittal, Luxembourg (LU)
PCT Filed Dec. 20, 2017, PCT No. PCT/IB2017/058187
§ 371(c)(1), (2) Date Jun. 5, 2019,
PCT Pub. No. WO2018/116192, PCT Pub. Date Jun. 28, 2018.
Claims priority of application No. PCT/IB2016/001788 (WO), filed on Dec. 20, 2016.
Prior Publication US 2019/0352738 A1, Nov. 21, 2019
This patent is subject to a terminal disclaimer.
Int. Cl. C21D 11/00 (2006.01); B22D 11/20 (2006.01); C21D 9/573 (2006.01); G06F 30/17 (2020.01); G06F 119/08 (2020.01)
CPC C21D 11/005 (2013.01) [B22D 11/202 (2013.01); C21D 9/573 (2013.01); G06F 30/17 (2020.01); G06F 2119/08 (2020.01)] 37 Claims
OG exemplary drawing
 
1. A method of dynamical adjustment for manufacturing a thermally treated steel sheet having a chemical steel composition and a microstructure mtarget comprising at least one phase chosen among: ferrite, martensite, bainite, pearlite, cementite and austenite, in a heat treatment line comprising a heating section, a soaking section and a cooling section including a cooling system, wherein a predefined thermal treatment TT, comprising at least a heating step, a soaking step and a cooling step, is performed, such method comprising:
performing the heating step of the predefined thermal treatment on a steel sheet in the heating section of the heat treatment line in accordance with a heating path Theating, the heating path Theating including a time, temperature and a heating rate;
performing the soaking step of the predefined thermal treatment on the steel sheet in the soaking section of the heat treatment line in accordance with a heating path Tsoaking, the heating path Tsoaking including a time, temperature and a soaking rate;
A. a control step wherein at least one detector detects any deviation happening during the heating step in the heating section of the heat treatment line or during the soaking step in the soaking section of the heat treatment line, the deviation being such that the predefined thermal treatment TT is determined to produce a microstructure different from mtarget,
B. a calculation step performed when a deviation is detected during the heating step in the heating section of the heat treatment line or during the soaking step in the soaking section of the heat treatment line such that a new thermal path TPtarget, performed as at least one further heat treatment step in the heat treatment line sequentially downstream from the performed at least one thermal treatment step, is determined to reach mtarget taking the deviation into account, such calculation step comprising:
1) a calculation sub-step wherein through variation of a cooling power of the cooling system of the cooling section of the heat treatment line in the cooling step, new cooling paths CPx are calculated based on TT, an initial microstructure mi of the steel sheet to reach mtarget, the heating path Theating and the soaking path Tsoaking the cooling step of TT being recalculated using said new cooling paths CPx in order to obtain new thermal paths TPx, having the cooling step replaced by one of the new cooling paths CPx in order to obtain a thermal path TPx, each TPx corresponding to a microstructure mx,
2) a selection step wherein one thermal path TPtarget, from amongst the thermal paths TPx calculated in the calculation substep, achieving the mx closest to mtarget is selected the selected thermal path TPtarget including a selected one of the new cooling paths CPx, and
C. performing a new thermal treatment step including the selected thermal path TPtarget online on the steel sheet, the performing of the new thermal treatment step including performing the selected new cooling path CPx on the steel sheet by the cooling system of the cooling section of the heat treatment line in place of the cooling step of the predefined thermal treatment.