ArcelorMittal S.A.
A METHOD FOR MANUFACTURING A THERMALLY TREATED STEEL SHEET

Abstract:

A method for manufacturing a thermally treated steel sheet is described. The method includes: A. a preparation step including: 1) a selection substep, wherein the chemical composition and m.sub.target are compared to a list of predefined products, which microstructure includes predefined phases and predefined proportion of phases, and selecting a product having a microstructure m.sub.standard closest to m.sub.target and a predefined thermal path TP.sub.standard to obtain m.sub.standard, 2) a calculation substep, wherein at least two thermal path TP.sub.x, each TP.sub.x corresponding to a microstructure mx obtained at the end of TP.sub.x, are calculated based on the selected product of step A.1) and TP.sub.standard and the initial microstructure mi of the steel sheet to reach m.sub.target, 3) an selection substep, wherein one thermal path TP.sub.target to reach m.sub.target is selected, TP.sub.target chosen from TP.sub.x and selected such that m.sub.x is the closest to m.sub.target, B. a thermal treatment step, wherein TP.sub.target is performed on the steel sheet.