US 12,325,889 B2
Hot rolled steel sheet and a method of manufacturing thereof
Sujay Sarkar, Metz (FR); Xavier Bano, Istres (FR); Guillaume Marcireau, Istres (FR); and Blandine Oehler, Pont-à-Mousson (FR)
Assigned to ArcelorMittal, Luxembourg (LU)
Appl. No. 17/279,546
Filed by ArcelorMittal, Luxembourg (LU)
PCT Filed Sep. 2, 2019, PCT No. PCT/IB2019/057381
§ 371(c)(1), (2) Date Mar. 24, 2021,
PCT Pub. No. WO2020/065422, PCT Pub. Date Apr. 2, 2020.
Claims priority of application No. PCT/IB2018/057549 (WO), filed on Sep. 28, 2018.
Prior Publication US 2021/0340642 A1, Nov. 4, 2021
Int. Cl. C21D 9/46 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/58 (2006.01)
CPC C21D 9/46 (2013.01) [C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/58 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01)] 19 Claims
 
1. A hot rolled steel sheet having a composition consisting of the following elements, expressed in percentage by weight:
0.11%≤Carbon≤0.16%,
1%≤Manganese≤2%,
0.1%≤Silicon≤0.7%,
0 02%≤Aluminum≤0.1%,
0.15%≤Molybdenum≤0.4%,
0.15%≤Vanadium≤0.4%,
0.002%≤Phosphorus≤0.02%,
0%≤Sulfur≤0.005%,
0%≤Nitrogen≤0.01%,
0%≤Chromium≤0.5%,
0%≤Niobium≤0.05%,
0.0001%≤Calcium≤0.005%,
0%≤Boron≤0.001%,
0%≤Magnesium≤0.0010%,
with 0.3%≤Mo+V+Nb≤0.6%,
a remainder of the composition being composed of iron and unavoidable impurities,
a microstructure of the hot rolled steel sheet comprising in area fraction, 70% to 90% Bainite, 10% to 25% Ferrite, wherein a cumulated amount of Bainite and Ferrite is at least 90% and a cumulated amount of Residual Austenite and Martensite is between 0% and 10%.