Low alloy third generation advanced high strength steel and process for making
AssigneeCleveland-Cliffs Inc.
InventorsLuis Gonzalo Garza-Martinez, Erik James Pavlina
Life of this patent
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Abstract
Prior third generation advanced high strength steels can produce ingots and hot bands that have a tendency to develop cracks. It has been found that an addition to third generation advanced high strength steels of one or more of molybdenum in an amount up to 0.50 wt % and nickel in an amount up to 1.5 wt %, eliminates the cracks in ingots, and improves the appearance of hot bands. More specifically the new exemplary alloys have shown to improve the toughness of ingots, as well as hot bands.
Claims17
A steel comprising 0.20 to 0.30 wt % carbon, 3.0 to 5.0 wt % manganese, 0.5 to 2.5 wt % silicon, 0.5 to 2.0 wt % aluminum, 0.25-0.5 wt % molybdenum, greater than 1.0% up to 1.5 wt % nickel;
- 0-0.050 wt % niobium, 0-1.0 wt % chromium, and the balance being iron and impurities associated with steelmaking, wherein the steel comprises 15-50% austenite by total area ratio, wherein a hot band comprised of the steel has a Charpy V-notch (“CVN”) impact testing energy above 20 J (14.75 ft-lbf) in a full size CVN specimen or 0.25 J/mm2 (1427 in-lbf/in{circumflex over ( )}2) in a thinner hot band, as measured at room temperature.
A steel comprising 0.20 to 0.30 wt % carbon, 3.0 to 5.0 wt % manganese, 0.5 to 2.5 wt % silicon, 0.5 to 2.0 wt % aluminum, 0.25-0.5 wt % molybdenum, 0.5-1.5 wt % nickel;
- 0-0.050 wt % niobium, 0-1.0 wt % chromium, and the balance being iron and impurities associated with steelmaking, wherein the steel comprises greater than 40% up to 50% austenite by total area ratio, wherein a hot band comprised of the steel has a Charpy V-notch (“CVN”) impact testing energy above 20 J (14.75 ft-lbf) in a full size CVN specimen or 0.25 J/mm2 (1427 in-lbf/in{circumflex over ( )}2) in a thinner hot band, as measured at room temperature.
Dependencies are inferred from the claim text.