公开(公告)号：US11725255B2

公开(公告)日：2023-08-15

申请号：US17311677

申请日：2018-12-18

Applicant: ArcelorMittal

Inventor： Blandine Remy ,  Thierry Sturel ,  Emmanuel Lucas ,  Gianni Boi

IPC: B21D22/02 ,  B32B15/01 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/50 ,  C22C38/54 ,  C21D9/46 ,  C21D6/00 ,  C21D8/02

CPC classification number: C21D9/46 ,  B21D22/02 ,  B32B15/012 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C22C38/001 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/50 ,  C22C38/54 ,  C21D2211/002 ,  C21D2211/004 ,  C21D2211/005 ,  C21D2211/008

Abstract: A press hardened coated steel part with high resistance to delayed fracture, the coating containing (Fex—Aly) intermetallic compounds resulting from the diffusion of iron into an aluminum or an aluminum-based alloy, or an aluminum alloy of a precoating, wherein the chemical composition of the steel includes, in weight: 0.16%≤C≤0.42%, 0.1%≤Mn≤3%, 0.07%≤Si≤1.60%, 0.002%≤Al≤0.070%, 0.02%≤Cr≤1.0%, 0.0005≤B≤0.005%, 0.002%≤Mg≤0.007%, 0.002%≤Ti≤0.11%, 0.0008%≤O≤0.005%, wherein (Ti)×(O)2×107≤2, 0.001%≤N≤0.007%, 0.001%≤S≤0.005%, 0.001%≤P≤0.025% and optionally one or more elements selected from the list of: 0.005%≤Ni≤0.23%, 0.005%≤Nb≤0.060%, the remainder being Fe and unavoidable impurities, and wherein the microstructure includes at least 95% martensite.

公开(公告)号：US12110572B2

公开(公告)日：2024-10-08

申请号：US16968880

申请日：2019-03-05

Applicant: ARCELORMITTAL

Inventor： Alexandre Blaise ,  Pascal Drillet ,  Thierry Sturel

IPC: C21D9/48 ,  C21D1/673 ,  C21D8/04 ,  C23C2/12 ,  C23C2/26 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/48 ,  C21D1/673 ,  C21D8/0484 ,  C23C2/12 ,  C23C2/261 ,  C23C2/28 ,  C23C2/29 ,  C23C2/40 ,  C21D2211/005 ,  C21D2211/009

Abstract: A process for manufacturing a non-stamped prealloyed steel coil, sheet or blank, comprising the following successive steps of: providing a non-stamped precoated steel coil, sheet or blank composed of a steel substrate covered by a precoating of aluminum, or aluminum-based alloy, or aluminum alloy, wherein the precoating thickness is comprised between 10 and 35 micrometers on each side of the steel coil, sheet or blank, then heating the non-stamped steel coil, sheet or blank in a furnace under an atmosphere containing at least 5% oxygen, up to a temperature θ1 comprised between 750 and 1000° C., for a duration t1 comprised between t1min and t1max, wherein: t1min=23500/(θ1−729.5) and t1max=4.946×1041×θ1−13.08, t1 designating the total duration in the furnace, θ1 being expressed in ° C. and t1min and t1max being expressed in seconds, then cooling the non-stamped steel coil, sheet or blank at a cooling rate Vr1 down to a temperature θi, then maintaining the non-stamped steel coil, sheet or blank at a temperature θ2 comprised between 100 and 500° C., for a duration t2 comprised between 3 and 45 minutes, so to obtain a diffusible hydrogen less than 0.35 ppm.

公开(公告)号：US11773464B2

公开(公告)日：2023-10-03

申请号：US17275157

申请日：2019-09-20

Applicant: ArcelorMittal

Inventor： Pascal Drillet ,  Raisa Grigorieva ,  Thierry Sturel ,  Cédric Georges ,  Brahim Nabi ,  Florin Duminica

IPC: C21D9/46 ,  C21D1/673 ,  C21D1/70 ,  C23C2/28 ,  B32B15/01 ,  C22C21/02 ,  C22C38/54 ,  C22C38/50 ,  C22C38/46 ,  C22C38/44 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/48

CPC classification number: C21D9/46 ,  B32B15/012 ,  B32B15/013 ,  C21D1/673 ,  C21D1/70 ,  C22C21/02 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C23C2/28 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

Abstract: A press hardening method includes the following steps providing a carbon steel sheet coated with a barrier pre-coating including nickel and chromium wherein the weight ratio Ni/Cr is between 1.5 and 9, cutting the sheet to obtain a blank, thermal treatment of the blank in an atmosphere having an oxidizing power equal or higher than that of an atmosphere consisting of 1% by volume of oxygen and equal or smaller than that of an atmosphere consisting of 50% by volume of oxygen, such atmosphere having a dew point between −30 and +30° C., transfer of the blank into a press tool, hot-forming of the blank to obtain a part, cooling of the part to obtain a microstructure in steel being martensitic or martensito-bainitic or made of at least 75 wt. % of equiaxed ferrite, from 5 to 20 wt. % of martensite and bainite in amount less than or equal to 10 wt. %.