公开(公告)号：US20230140215A1

公开(公告)日：2023-05-04

申请号：US17740472

申请日：2022-05-10

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Qi LU ,  Jianfeng WANG ,  Zhisong CHAI ,  Wei XU

IPC: C21D9/46 ,  C21D1/673 ,  C22C38/48 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C21D6/00 ,  B21D22/02

Abstract: Methods include pressing and quenching a heated blank in a die to form the shaped steel object. A first portion of the heated blank is selectively cooled at a first cooling rate and a second portion of the heated blank selectively cooled at a lower second cooling rate. The shaped steel object has an alloy with wt. % of chromium at ≥about 0.5 to ≤about 6; carbon at ≥about 0.01 to ≤about 0.5; manganese at ≥about 0 to ≤about 3; silicon at ≥about 0.5 to ≤about 2; nitrogen at ≥0 to ≤about 0.01; nickel at ≥0 to ≤about 5; copper at ≥0 to ≤about 5; molybdenum at ≥0 to ≤about 5; vanadium at ≥0 to ≤about 1%; niobium at ≥0 to ≤about 0.1; and a balance being iron.

公开(公告)号：US20230383374A1

公开(公告)日：2023-11-30

申请号：US17873926

申请日：2022-07-26

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC ,  Northeastern University

Inventor： Zhou WANG ,  Zhisong CHAI ,  Wei XU ,  Jianfeng WANG

IPC: C21D9/46 ,  C21D6/00 ,  C21D1/613 ,  C22C38/48 ,  C22C38/46 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/50

CPC classification number: C21D9/46 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D1/613 ,  C22C38/48 ,  C22C38/46 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/50 ,  C21D2211/008 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005

Abstract: The present disclosure provides a method for preparing a steel alloy sheet to enhance flatness. The method includes, inter alia, heating a steel alloy material to a first temperature that is greater than a full-austenitization point for the steel alloy material; holding steel alloy material at the first temperature for a period greater than or equal to about 1 second to less than or equal to about 10,000 seconds to from a precursor steel sheet; air quenching the precursor steel sheet to a second temperature that is less than the first temperature and greater than martensitic transformation starting temperature for the steel alloy material; and cooling the precursor steel sheet to room temperature to prepare the steel alloy sheet. The steel alloy material includes greater than or equal to about 0.5 wt. % to less than or equal to about 6 wt. % of chromium.

公开(公告)号：US20240052445A1

公开(公告)日：2024-02-15

申请号：US17965312

申请日：2022-10-13

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC ,  NORTHEASTERN UNIVERSITY

Inventor： Zhisong CHAI ,  Tingdong REN ,  JinLong ZHU ,  Wei XU ,  Jianfeng WANG

IPC: C21D1/673 ,  C21D1/18 ,  B21D22/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/18

CPC classification number: C21D1/673 ,  C21D1/18 ,  B21D22/022 ,  C22C38/02 ,  C22C38/04 ,  C22C38/18 ,  C21D2211/008 ,  C21D2211/001

Abstract: A method for preparing a press-hardened steel component is provided. The method includes forming a heated blank by heating a steel alloy blank to a first temperature in a first zone of a furnace having two or more zones, and after the heating of the steel alloy blank to the first temperature, heating the steel alloy blank to a second temperature in a second zone of the furnace. The second temperature is greater than the first temperature. The first zone has a first flow rate for a protective gas, and the second zone has a second flow rate for the protective gas that is greater than the first flow rate. The method further includes stamping and quenching the heated blank at a constant rate to a temperature between a martensite finish temperature of the steel alloy defining the steel alloy blank and room temperature to form the press-hardened steel component.