1500 MPa grade press hardening steel by thin slab casting and direct rolling and method for producing the same

US10995380B2 · kind B2 · utility

Assignee

• WUHAN IRON AND STEEL CORP. · CN

Inventors

• Xinping MAO · Hubei, CN
• Kuanhui Hu · Hubei, CN
• Shuize WANG · Hubei, CN
• Libo Pan · Hubei, CN
• Rui GE · Nanjing, CN
• Lijun Li · Qingdao, CN
• Tao Peng · Longbeilingcun, CN
• Xiaofeng Du · London, GB
• Wenqiang ZHOU · Hubei, CN

Key dates

• Filing date: Aug 1, 2017
• Grant date: May 4, 2021
• Expiry date: Jan 10, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D8/0231
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A press hardening steel by a thin slab casting and direct rolling has a tensile strength of 1500 MPa or more. The press hardening steel has a components by weight percent: C: 0.21-0.25%, Si: 0.26-0.30%, Mn: 1.0-1.3%, P≤0.01%, S≤0.005%, Als: 0.015-0.060%, Cr: 0.25-0.30%, Ti: 0.026-0.030% or Nb: 0.026-0.030% or V: 0.026-0.030%, or a mixture of two or more of the above in any proportion; B: 0.003-0.004%, and N≤0.005%. A method for producing the press hardening steel includes following steps: hot metal desulphurization; electric-furnace or converter smelting and refining; continuous casting; descaling, then entering a soaking furnace; heating and soaking; high-pressure water descaling, then entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.