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

US10988820B2 · 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
• Fang Fang · Yokohama, JP

Key dates

• Filing date: Aug 1, 2017
• Grant date: Apr 27, 2021
• Expiry date: Jan 10, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D9/46
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A press hardening steel by a medium thin slab and having a tensile strength of 1500 MPa or more, includes following 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 any two or more of the above in any proportion, B: 0.003%-0.004%, Mo: 0.17-0.19% 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; hating and soaking; high pressure water descaling before entering a rolling mill; hot rolling; cooling; coiling; austenitizing; die deforming and quenching.