公开(公告)号：US12221705B2

公开(公告)日：2025-02-11

申请号：US18251269

申请日：2021-11-05

Applicant: JFE STEEL CORPORATION

Inventor： Shunsuke Yamamoto ,  Katsutoshi Takashima ,  Mai Aoyama ,  Yusuke Okumura ,  Tomomi Kanazawa ,  Katsuya Hoshino ,  Hiroshi Matsuda ,  Ei Okumura ,  Yoichi Makimizu ,  Masaki Koba

IPC: C23C28/02 ,  C21D1/74 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C33/04 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/26 ,  C23C2/28 ,  C25D3/20 ,  C25D5/36 ,  C23C2/06 ,  C23C2/40

Abstract: Provided is an alloyed galvanized steel sheet with excellent resistance to cracking in resistance welding at a welded portion, even if crystal orientations of an Fe-based electroplating layer and a cold-rolled steel sheet are integrated at a high ratio at the interface between the Fe-based electroplating layer and the cold-rolled steel sheet. The alloyed galvanized steel sheet has a Si-containing cold-rolled steel sheet containing Si in an amount of 0.1 mass % to 3.0 mass %; an Fe-based electroplating layer formed on at least one surface of the Si-containing cold-rolled steel sheet with a coating weight per surface exceeding 20.0 g/m2, and an alloyed galvanized layer formed on the Fe-based electroplating layer, where crystal orientations of the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet are integrated at a ratio of more than 50% at the interface between the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet.

公开(公告)号：US20240271256A1

公开(公告)日：2024-08-15

申请号：US18289928

申请日：2022-05-17

Applicant: JFE Steel Corporation

Inventor： Yoichi Makimizu ,  Shunsuke Yamamoto ,  Yusuke Okumura ,  Katsuya Hoshino ,  Ei Okumura ,  Katsutoshi Takashima

IPC: C22C38/04 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C23C2/26 ,  C23C28/02

CPC classification number: C22C38/04 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C23C2/26 ,  C23C28/025

Abstract: A base steel sheet containing Si in an amount of 0.50 to 3.00 mass % is subjected to an Fe-based electroplating treatment using an Fe-based electroplating solution containing Fe ions and transition metal ions other than the Fe ions to form an Fe-based electroplated layer, and then to an annealing treatment. In the Fe-based electroplating solution, a content of the Fe ions is 1.0 mass % or more and a content of the transition metal ions is 10 to 1000 mass ppm. A coating amount of the Fe-based electroplated layer per one surface of the base steel sheet is 1.0 g/m2 or more. Thus, a steel sheet having high strength and excellent resistance to resistance-weld cracking of a welded portion is obtained.