公开(公告)号：US20240392405A1

公开(公告)日：2024-11-28

申请号：US18693424

申请日：2021-09-29

Applicant: ArcelorMittal

Inventor： Tom WATERSCHOOT ,  Arunim RAY ,  Rénald DAVID

IPC: C21D9/46 ,  C21D1/18 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12

Abstract: A cold rolled and heat treated steel sheet having a composition including of the following elements, 0.05%≤Carbon≤0.12%, 1.0%≤Manganese≤2%, 0.01%≤Silicon≤0.5%, 0.01%≤Aluminum≤0.1%, 0.01%≤Niobium≤0.1%, 0%≤Phosphorus≤0.09%, 0%≤Sulfur≤0.09%, 0%≤Nitrogen≤0.09%, 0.1%≤Chromium≤0.5%, 0%≤Nickel≤3%, 0%≤Titanium≤0.1%, 0%≤Calcium≤0.005%, 0%≤Copper≤2%, 0%≤Molybdenum≤0.5%, 0%≤Vanadium≤0.1%, 0%≤Boron≤0.003%, 0%≤Cerium≤0.1%, 0%≤Magnesium≤0.010%, 0%≤Zirconium≤0.010% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet including in area fraction, 50 to 90% Recrystallized ferrite, 10 to 50% non-recrystallized ferrite, 0% to 15% Cementite and 0.5% to 2% Carbides of Niobium, wherein the cumulated amount of Recrystallized ferrite and Non-recrystallized ferrite is at least 85%.