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公开(公告)号：US11255006B2
公开(公告)日：2022-02-22
申请号：US16509001
申请日：2019-07-11
Applicant: GM Global Technology Operations LLC
Abstract: A steel alloy workpiece and a method for making a press-hardened steel (PHS) component using the steel alloy workpiece is provided. The steel alloy workpiece includes between about 1.0 and 5.0 weight percent chromium, between about 0.5 and 2.0 weight percent silicon, and a surface having a predetermined imprinted pattern. The imprinted pattern includes one of a plurality of overlapping nested sinusoidal waves and a honey-comb pattern, and ascribes a surface roughness of between about 1.0 microns and 2.5 microns. The method includes providing the steel alloy workpiece, heating the workpieces at a predetermined time and temperature, hot stamping the workpieces into the PHS component, quenching the PHS component at a predetermined quench rate, and e-coating the PHS component. The e-coating is applied directly onto the surface of the PHS component.
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公开(公告)号：US10675701B2
公开(公告)日：2020-06-09
申请号：US15638699
申请日：2017-06-30
Applicant: GM Global Technology Operations LLC
Inventor： David Yang , Wu Tao , Qi Lu , Blair E Carlson
Abstract: A method of resistance spot welding a workpiece stack-up comprising overlapping first and second steel workpieces is disclosed, wherein at least one of the steel workpieces comprises an advanced high-strength steel substrate. The workpiece stack-up is positioned between a pair of opposed first and second welding electrodes. A cover is disposed between at least one of the first steel workpiece and the first welding electrode or the second steel workpiece and the second welding electrode at an intended weld site. The workpiece stack-up is clamped between the first and second welding electrodes at the weld site such that at least one of the weld faces of the first and second welding electrodes presses against the cover. The first and second steel workpieces are welded together by passing an electrical current between the first and second welding electrodes at the weld site.
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公开(公告)号：US20200157665A1
公开(公告)日：2020-05-21
申请号：US16509001
申请日：2019-07-11
Applicant: GM Global Technology Operations LLC.
Abstract: A steel alloy workpiece and a method for making a press-hardened steel (PHS) component using the steel alloy workpiece is provided. The steel alloy workpiece includes between about 1.0 and 5.0 weight percent chromium, between about 0.5 and 2.0 weight percent silicon, and a surface having a predetermined imprinted pattern. The imprinted pattern includes one of a plurality of overlapping nested sinusoidal waves and a honey-comb pattern, and ascribes a surface roughness of between about 1.0 microns and 2.5 microns. The method includes providing the steel alloy workpiece, heating the workpieces at a predetermined time and temperature, hot stamping the workpieces into the PHS component, quenching the PHS component at a predetermined quench rate, and e-coating the PHS component. The e-coating is applied directly onto the surface of the PHS component.
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公开(公告)号：US10329639B2
公开(公告)日：2019-06-25
申请号：US15668751
申请日：2017-08-04
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Inventor： Charles Enloe , Curt D. Horvath , David Yang , Qi Lu , Wu Tao
IPC: C21D9/46 , C21D8/02 , C21D3/04 , C23C2/06 , B32B15/01 , B23K11/11 , B23K11/16 , B23K26/22 , B23K26/322 , C23C30/00 , C23C2/28 , C23C2/40 , C23C2/02 , C23C2/26 , B23K103/16
Abstract: A multilayer steel includes a core formed of transformation-induced plasticity (TRIP) steel. A decarburized layer is exterior to the core on at least one side thereof. The decarburized layer has reduced carbon content relative to the core. A zinc-based layer is exterior to the decarburized layer. The decarburized layer may have a composition of at least 80 percent ferrite, such that LME is reduced or mitigated. In some configurations, the decarburized layer is between 10-50 microns thick. A method of creating a coated advanced high-strength steel component is also provided. An apparatus for forming a coated advanced high-strength steel is also provided. The core of the multilayer steel may have a carbon weight-percent of less than or equal to 0.4. The decarburized layer of the multilayer steel may have a carbon weight-percent of less than or equal to 50 percent of the carbon weight-percent of the core.
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公开(公告)号：US10260121B2
公开(公告)日：2019-04-16
申请号：US15426518
申请日：2017-02-07
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Inventor： Qi Lu , Jianfeng Wang
IPC: C21D1/19 , C21D1/40 , C21D1/42 , C21D1/52 , C21D8/00 , C21D9/00 , C21D1/673 , C22C38/02 , C22C38/06 , C22C38/22 , C22C38/34 , C22C38/38
Abstract: In a method for increasing steel impact toughness, the steel composition contains from about 5 wt % to about 10 wt % manganese and has a martensite finish temperature (Mf) below room temperature. The steel composition is exposed to hot forming to form a steel part. During hot forming, the steel composition is subjected to a heat treatment temperature above its fully austenite formed temperature, is transferred to a die, and while in the die, is simultaneously formed and quenched. In one example, quenching cools the steel composition to room temperature, and the steel part is removed from the die and reheated to a baking temperature ranging from about 120° C. to about 400° C. In another example, quenching is interrupted at an interruption temperature ranging from about 120° C. to about 400° C., and the steel composition is maintained at the interruption temperature for a predetermined time and then is cooled to room temperature.
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Patent Agency Ranking
公开(公告)号：US20180216205A1
公开(公告)日：2018-08-02
申请号：US15417921
申请日：2017-01-27
Applicant: GM Global Technology Operations LLC
Inventor： Jianfeng Wang , Qi Lu , Anil K. Sachdev
CPC classification number: C21D9/0068 , B21D22/022 , B21D35/005 , B32B15/013 , C21D1/18 , C21D6/005 , C21D8/005 , C21D2211/001 , C21D2211/008 , C22C38/04 , C23C2/06 , C23C2/26 , C23C2/28 , C23C2/40
Abstract: Methods for press hardening steel alloys comprised of medium-Mn are provided. The press-hardened steel alloy may have an ultimate tensile strength (UTS) of at least 1,700 MPa and a tensile elongation of at least 8%. The press-hardened steel alloy may be formed in two forming steps above the martensitic finish temperature. The press-hardened steel may have a microstructure comprising martensite at greater than or equal to about 80% to less than or equal to about 98% and retained austenite at less than or equal to about 20% to greater than or equal to about 2%.
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公开(公告)号：US20230235424A1
公开(公告)日：2023-07-27
申请号：US17889812
申请日：2022-08-17
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Inventor： Qi Lu , Zhou Wang , Jianfeng Wang
CPC classification number: C21D9/52 , C22C38/38 , C22C38/34 , C21D8/0221 , C21D8/0205 , C21D6/008 , C21D6/005 , C21D6/002 , C21D2221/00 , C21D2211/008
Abstract: A method of forming a component having a cross-section with a bend radius includes providing a work-piece blank from press-hardened steel (PHS). The method also includes austenitizing the work-piece blank in a furnace via heating the strip of sheet metal to achieve therein an austenite microstructure, including soaking the work-piece blank for a predetermined amount of time. The method additionally includes quenching the austenitized work-piece blank to achieve therein a martensitic matrix microstructure with dispersed chromium-enriched carbide. The method also includes roll-forming the austenitized and quenched work-piece blank to generate the cross-section and the bend radius. The method may further include locally heating the bend radius area during the roll-forming of the cross-section to reduce an amount of chromium-enriched carbide in the martensitic matrix microstructure inside the bend radius area relative to the microstructure outside the bend, and thereby generating the component having high strength, ductility, and wear resistance.
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公开(公告)号：US20190071747A1
公开(公告)日：2019-03-07
申请号：US15698114
申请日：2017-09-07
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Abstract: A method of heat treating a steel workpiece may include two heat treatment stages. In the first stage, the steel workpiece may be heated to a first temperature greater than or equal to its A1 temperature, but less than its A3 temperature to transform the microstructure of the steel workpiece into a multiphase microstructure including grains of ferrite and grains of austenite having an average grain diameter. In the second stage, the steel workpiece may be heated to a second temperature greater than the first temperature to increase the average grain diameter of the grains of austenite. Thereafter, the steel workpiece may be cooled to ambient temperature at a rate sufficient to retain a major portion of the grains of austenite obtained during the first and second heat treatment stages. The as-heat treated steel workpiece may comprise a retained austenite phase dispersed within a ferrite matrix phase at ambient temperature.
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公开(公告)号：US11951522B2
公开(公告)日：2024-04-09
申请号：US18123592
申请日：2023-03-20
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Inventor： Jiachen Pang , Qi Lu , Jianfeng Wang
IPC: B21D22/02 , C21D1/19 , C21D1/673 , C21D1/76 , C21D6/00 , C22C38/04 , C22C38/06 , C22C38/12 , C22C38/14
CPC classification number: B21D22/022 , C21D1/19 , C21D1/673 , C21D1/76 , C21D6/005 , C22C38/04 , C22C38/06 , C22C38/12 , C22C38/14 , C21D2211/001 , C21D2211/008
Abstract: A method of forming a shaped steel object is provided. The method includes cutting a blank from an alloy composition including 0.05-0.5 wt. % carbon, 4-12 wt. % manganese, 1-8 wt. % aluminum, 0-0.4 wt. % vanadium, and a remainder balance of iron. The method also includes heating the blank until the blank is austenitized to form a heated blank, transferring the heated blank to a press, forming the heating blank into a predetermined shape to form a stamped object, and decreasing the temperature of the stamped object to a temperature between a martensite start (Ms) temperature of the alloy composition and a martensite final (Mf) temperature of the alloy composition to form a shaped steel object comprising martensite and retained austenite.
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公开(公告)号：US11794280B2
公开(公告)日：2023-10-24
申请号：US17725813
申请日：2022-04-21
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Inventor： Mingfeng Shi , Sarah Tedesco , Qi Lu , Jason J. Coryell , Jianfeng Wang
IPC: C22C38/46 , C22C38/44 , C22C38/42 , C22C38/02 , C22C38/04 , B23K26/26 , C21D9/50 , C22C38/48 , C21D6/00 , B21D22/02
CPC classification number: B23K26/26 , B21D22/022 , C21D6/004 , C21D6/005 , C21D6/008 , C21D9/50 , C22C38/02 , C22C38/04 , C22C38/42 , C22C38/44 , C22C38/46 , C22C38/48 , C21D2211/001
Abstract: A hot formed joined blank includes a first metal blank having an ultimate tensile strength of ≥about 1300 MPa to ≤about 2000 MPa and defining a first surface, a second metal blank having an ultimate tensile strength of ≥about 400 MPa to ≤about 1200 MPa and defining a second coated surface having a coating disposed thereon. The coating includes aluminum and silicon or in alternative variations, zinc. A third surface of the second metal blank is joined to the first surface of the first metal blank to form the hot formed joined blank. A weld nugget is disposed along a boundary between the first and second metal blanks that is configured to join the first and second metal blanks, where the weld nugget optionally includes less than or equal to about 1.5 weight percent aluminum or a microstructure comprising austenite and delta-ferrite.
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