公开(公告)号：US11655519B2

公开(公告)日：2023-05-23

申请号：US16488437

申请日：2018-02-27

Applicant: NUCOR CORPORATION

Inventor： James W. Watson ,  Paul Kelly ,  Mike Schueren ,  Walter N. Blejde

IPC: C21D9/52 ,  C22C38/48 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  B22D11/00 ,  B22D11/06 ,  B22D11/12 ,  C21D6/00 ,  C21D1/18 ,  C22C38/46

CPC classification number: C21D9/52 ,  B22D11/001 ,  B22D11/0622 ,  B22D11/1213 ,  C21D1/18 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C21D2211/008

Abstract: This application discloses thin metal strips and methods of making thin metal strip. Particular embodiments of such methods include cooling the thin metal strip to a temperature equal to or less than a bainite or a martensite start transformation temperature BS or MS to thereby form bainite and/or martensite, respectively, within the thin metal strip, reheating the thin metal strip to a reheat temperature equal to or greater than transformation temperature Ac3 and holding the thin metal strip at the reheat temperature for at least 2 seconds and thereby forming austenite within the thin metal strip with at least 75% of austenite grains having a grain size equal to or less than 15 μm, and rapidly recooling the thin metal strip to a temperature equal to or less than the martensite start transformation temperature MS and thereby providing finer martensite within the thin metal strip from a finer prior austenite.

公开(公告)号：US11773465B2

公开(公告)日：2023-10-03

申请号：US16944377

申请日：2020-07-31

Applicant: NUCOR CORPORATION

Inventor： Kishlay Mishra ,  Paul Kelly ,  Tao Wang

IPC: B21D22/22 ,  C21D9/52 ,  C22C38/46 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/48 ,  B21D22/02 ,  C21D9/48 ,  C21D9/56

CPC classification number: C21D9/52 ,  B21D22/022 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0215 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D9/48 ,  C21D9/563 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/46 ,  C22C38/48 ,  C21D2211/002 ,  C21D2211/008

Abstract: Disclosed herein is a light-gauge, ultra-high strength weathering steel sheet with a composition, material properties, and surface characteristics that make it suitable for hot-stamping applications and making hot-stamped products. Also disclosed herein is a high friction rolled carbon alloy steel strip free of prior austenite grain boundary depressions and having a smear pattern. Still further disclosed herein is a high friction rolled carbon alloy steel strip that has been surface homogenized to provide a thin cast steel strip free of a smear pattern.

公开(公告)号：US11225697B2

公开(公告)日：2022-01-18

申请号：US14974628

申请日：2015-12-18

Applicant: NUCOR CORPORATION

Inventor： James W. Watson ,  Paul Kelly ,  David C. Van Aken ,  Christopher Ronald Killmore

IPC: C21D8/02 ,  B22D11/00 ,  B22D11/06 ,  C21D6/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/26 ,  C22C38/38

Abstract: A hot rolled light-gauge martensitic steel sheet made by the steps comprising: (a) preparing a molten steel melt comprising: (i) by weight, between 0.20% and 0.35% carbon, less than 1.0% chromium, between 0.7% and 2.0% manganese, between 0.10% and 0.50% silicon, between 0.1% and 1.0% copper, less than 0.05% niobium, less than 0.5% molybdenum, and silicon killed containing less than 0.01% aluminum, and (ii) the remainder iron and impurities resulting from melting; (b) solidifying at a heat flux greater than 10.0 MW/m2 and cooling the molten melt into a steel sheet less than 2.0 mm in thickness in a non-oxidizing atmosphere to below 1080° C. and above Ar3 temperature at a cooling rate greater than 15° C./s; and (c) hot rolling the steel sheet to between 15% and 50% reduction and rapidly cooling.