Two-step hot forming of steels

Abstract

Methods for press hardening steel alloys comprised of medium-Mn are provided. The press-hardened steel alloy may have an ultimate tensile strength (UTS) of at least 1,700 MPa and a tensile elongation of at least 8%. The press-hardened steel alloy may be formed in two forming steps above the martensitic finish temperature. The press-hardened steel may have a microstructure comprising martensite at greater than or equal to about 80% to less than or equal to about 98% and retained austenite at less than or equal to about 20% to greater than or equal to about 2%.

Description

INTRODUCTION[0001]This section provides background information related to the present disclosure which is not necessarily prior art.[0002]The present disclosure relates to two-step forming methods of press-hardening steel alloys to form high-strength press-hardened components.[0003]Press-hardened steel (PHS), also referred to as “hot-stamped steel,” is one of the strongest steels used for automotive body structural applications, having tensile strength properties on the order of about 1,500 mega-Pascal (MPa) and total elongation on the order of about 5% to 6%. Such steel has many desirable properties and uses, including forming steel components with significant increases in strength-to-weight ratios. Further, PHS components have become increasingly prevalent in various industries and applications, including general manufacturing, construction equipment, automotive or other transportation industries, home or industrial structures, and the like. For example, in automotive manufacturin...

AI Technical Summary

Benefits of technology

Press-hardened steel (PHS) is a strong steel used for automotive body structures, which has high tensile strength and elongation properties. It allows for the formation of stronger and lighter steel components, and is increasingly being used in other industries like manufacturing and construction. PHS components can provide high strength and resistance to external forces, while also providing cathodic protection. The final state of the steel is designed to have the required strength and ductility to protect passengers from intrusion during a collision.

Problems solved by technology

After shot blasting, further forming of the PHS component is typically accomplished with laser cutting, as die cutting is typically not effective given the high strength of the PHS component.

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