Tailored Properties By Post Hot Forming Processing

Abstract

A method of forming a product from an initial blank comprises subjecting the initial blank to a hot forming and press hardening operation to form the product with substantially a uniform first tensile strength. Subsequently, the product is subjected to post hot-forming processing in which a first region of the product is heated selectively to above a known temperature, using one of conduction heating, resistance heating, and induction heating. The first region is then cooled, such that the first region attains a second tensile strength that is substantially less than the first tensile strength.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. provisional application Ser. No. 61 / 358,174 filed Jun. 24, 2010, the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.FIELD OF THE INVENTION[0002]The instant invention relates generally to metallic products having tailored properties, and more particularly to a method of producing regions of reduced hardness and reduced strength in products via post hot-forming processing.BACKGROUND OF THE INVENTION[0003]In the field of vehicle construction, more and more vehicle parts that are made of high-strength and ultra-high-strength steel are being employed in order to satisfy criteria for lightweight construction. This applies to car body construction where, in order to meet weight goals and safety requirements, for instance structural and / or safety elements such as door intrusion beams, A and B columns, bumpers, side ra...

AI Technical Summary

Benefits of technology

[0012]According to an embodiment, other regions of the product are cooled or at least insulated from being heated to the known temperature as a result of the one of conduction heating, resistance heating and induction heating. For instance, the product is gripped using a cooled collar that surrounds a second region of the product that is adjacent to the first region. Alternatively, the second region of the product is protected from being heated using a curtain of a cooled gas, such as for instance air, or by spraying or misting the second region with a suitable cooling liquid, such as for instance water.

Problems solved by technology

Unfortunately, the die halves must be specially made for each part, which is both laborious and costly.

In addition, special effort is required in order to minimize the extent of formation of transition regions between the different portions, since typically these transition regions exhibit properties that are less well defined than the properties of the rest of the finished product.

Unfortunately, the use of highly specialized laser equipment adds to the cost and complexity of manufacturing the component.

In addition, this approach is not well suited either to batch processing or to applications requiring the formation of substantial regions having reduced tensile strength within the component.

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