Steel material for hot stamping, hot stamping process and hot stamped component

US11377703B2 · kind B2 · utility

Assignees

• Northwestern University · US
• Bengang Steel Plates Co., Ltd. · CN

Inventors

• Hongliang Yi · 东风镇, CN
• Hongliang Liu · Qinzhou City, CN
• Zhiyuan Chang · Xi'an, CN
• Di Wu · Danbury, US
• Jian-Jia Huang · Taoyuan, TW
• Guodong Wang · Changchun, CN

Key dates

• Filing date: Sep 8, 2016
• Grant date: Jul 5, 2022
• Expiry date: Sep 14, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C38/12
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to a steel material for hot stamping with ultra-fine grains and a process of making the same, a hot stamping process and a hot stamped component. The steel material for hot stamping comprises the following components by weight: 0.27 to 0.40% of C; 0.2 to 3.0% of Mn; 0.11 to 0.4% of V; 0 to 0.8% of Si; 0 to 0.5% of Al; 0 to 2% of Cr; 0 to 0.15% of Ti; 0 to 0.15% of Nb; 0 to 0.004% B; a total of less than 2% of Mo, Ni, Cu and other alloying elements that are beneficial to improving the hardenability, and other impurity elements. After hot stamping or equivalent heat treatment, the steel material or the formed component of the present invention can achieve a yield strength of 1300 MPa to 1700 MPa, a tensile strength of 1800 to 2200 MPa, and an elongation of 6 to 9% after direct hot stamping quenching and without tempering, which properties cannot be achieved by a material with a composition in the prior art in the situation of direct quenching (no tempering). After the tempering treatment of the present invention, preferably 1500 MPa-1900 MPa-8%, and 1600 MPa-2100 MPa-7% can be reached.