1900 MPa grade press hardening steel by thin slab casting and directly rolling and method for producing the same

US11124851B2 · kind B2 · utility

Assignee

• WUHAN IRON AND STEEL CORP. · CN

Inventors

• Xinping MAO · Hubei, CN
• Libo Pan · Hubei, CN
• Kuanhui Hu · Hubei, CN
• Shuize WANG · Hubei, CN
• Rui GE · Nanjing, CN
• Lijun Li · Qingdao, CN
• Tao Peng · Longbeilingcun, CN
• Xiaoping Duan · Hubei, CN
• Fang Fang · Yokohama, JP

Key dates

• Filing date: Aug 1, 2017
• Grant date: Sep 21, 2021
• Expiry date: Jun 12, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/008
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A press hardening steel by a thin slab and having a tensile strength of 1900 MPa or more includes following components by weight: C: 0.31-0.40%, Si: 0.36-0.44%, Mn: 1.6-2.0%, P≤0.006%, S≤0.004%, Als: 0.015-0.060%, Cr: 0.36-0.49%, Ti: 0.036-0.045% or Nb: 0.036-0.045% or V: 0.036-0.045% or a mixture of any two or more of the above in any proportion, B: 0.004-0.005%, Mo: 0.26-0.35%, and N≤0.005%. A method for producing the press hardening steel includes following steps: molten iron desulphurization; smelting and refining by an electric furnace or converter; continuous casting; descaling treatment before entering a soaking furnace; heating and soaking; high pressure water descaling before entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.